3 men, 1 woman, 350 bags found

• Magazine writer says he met the actor in Utah two weeks before his death


• "He took off his hat and he said, 'I'm a heroin addict,' " writer says of Hoffman


• Source: Heroin recovered does not contain fentanyl


• Such a combination has claimed lives in Maryland and Pennsylvania

New York (CNN) -- Four people thought to be connected to the drugs found in late actor Philip Seymour Hoffman's apartment were arrested Tuesday night, a law enforcement official told CNN.

During the raid that yielded the arrest of the three men and one woman, police recovered 350 glassine bags, the official said.

No additional information was released.

Hoffman's final hours

When police were called to Hoffman's fourth-floor Manhattan apartment Sunday, they found the actor lying on the bathroom floor with a syringe in his left arm. He was wearing shorts and a T-shirt, his eyeglasses still resting on his head, according to law enforcement sources familiar with the inquiry.

Journalist: Hoffman 'wasn't quite right'

Naloxone: Could it have saved Hoffman?

Investigators discovered close to 50 envelopes of what they believed was heroin in the apartment, the law enforcement sources said. They also found used syringes, prescription drugs and empty bags that authorities suspect are used to hold heroin, the sources said.

How heroin kills you

Preliminary tests Tuesday showed the heroin recovered from the apartment does not contain fentanyl, a law enforcement official told CNN.

More testing will be done, but as of now no fentanyl has been detected.

Fentanyl is a powerful narcotic used to treat cancer patients' pain.

Last week, Maryland officials said heroin tainted with fentanyl had claimed at least 37 lives since September. And last month, at least 22 people died after using heroin mixed with fentanyl in western Pennsylvania.

Hoffman revealed last year that he had entered rehab to deal with a drug problem, telling TMZ that he'd kicked a substance abuse habit for 23 years.

In a 2011 interview with "60 Minutes," he discussed his past struggles with drug and alcohol addiction.

"Anything I could get my hands on, I liked it all," he said.

Fear, Hoffman said, made him sober up.

"You get panicked. ... I was 22 and I got panicked for my life, it really was, it was just that," he said. "And I always think, 'God, I have so much empathy for these young actors that are 19 and all of a sudden are beautiful and famous and rich.' I'm like, 'Oh my God. I'd be dead.'"

Last year, Hoffman said he'd fallen off the wagon, started taking prescription pills and slipped into snorting heroin, according to TMZ.

Magazine writer John Arundel said he met the actor at the Sundance Film festival in Utah two weeks before his death.

"I said, 'what do you do? And at that point, he took off his hat and he said, 'I'm a heroin addict,' " Arundel said. "Didn't look like he was (joking). Seemed like he was having one of those 'coming to God' moments- where it just stuck him as, 'this is the revelatory moment.'"

Family and close friends of the actor will hold a private funeral service in New York. Plans are also under way for a memorial service later this month. No information on the dates was available.

4 arrests in connection with Hoffman drugs

• Source: Heroin recovered does not contain fentanyl


• Such a combination has claimed lives in Maryland and Pennsylvania

New York (CNN) -- New York police have taken in for questioning four people who are believed to be connected to the drugs found in late actor Philip Seymour Hoffman's apartment, a New York law enforcement official told CNN Tuesday night.

No additional information was released.

Hoffman's final hours

When police were called to Hoffman's fourth-floor Manhattan apartment Sunday, they found the actor lying on the bathroom floor with a syringe in his left arm. He was wearing shorts and a T-shirt, his eyeglasses still resting on his head, according to law enforcement sources familiar with the inquiry.

Journalist: Hoffman 'wasn't quite right'

Naloxone: Could it have saved Hoffman?

Investigators discovered close to 50 envelopes of what they believed was heroin in the apartment, the law enforcement sources said. They also found used syringes, prescription drugs and empty bags that authorities suspect are used to hold heroin, the sources told CNN.

How heroin kills you

Also Tuesday, preliminary tests showed the heroin recovered from the apartment does not contain fentanyl, a law enforcement official told CNN.

More testing will be done, but as of now no fentanyl has been detected.

Fentanyl is a powerful narcotic used to treat cancer patients' pain.

Last week, Maryland officials said that heroin tainted with fentanyl had claimed at least 37 lives since September. And last month, at least 22 people in western Pennsylvania died after using heroin that had been mixed with fentanyl.

Heroin in home had no fentanyl

• Source: Heroin recovered does not contain fentanyl


• Such a combination has claimed lives in Maryland and Pennsylvania

New York (CNN) -- New York police have taken in for questioning four people who are believed to be connected to the drugs found in late actor Philip Seymour Hoffman's apartment, a New York law enforcement official told CNN Tuesday night.

No additional information was released.

Hoffman's final hours

When police were called to Hoffman's fourth-floor Manhattan apartment Sunday, they found the actor lying on the bathroom floor with a syringe in his left arm. He was wearing shorts and a T-shirt, his eyeglasses still resting on his head, according to law enforcement sources familiar with the inquiry.

Journalist: Hoffman 'wasn't quite right'

Naloxone: Could it have saved Hoffman?

Investigators discovered close to 50 envelopes of what they believed was heroin in the apartment, the law enforcement sources said. They also found used syringes, prescription drugs and empty bags that authorities suspect are used to hold heroin, the sources told CNN.

How heroin kills you

Also Tuesday, preliminary tests showed the heroin recovered from the apartment does not contain fentanyl, a law enforcement official told CNN.

More testing will be done, but as of now no fentanyl has been detected.

Fentanyl is a powerful narcotic used to treat cancer patients' pain.

Last week, Maryland officials said that heroin tainted with fentanyl had claimed at least 37 lives since September. And last month, at least 22 people in western Pennsylvania died after using heroin that had been mixed with fentanyl.

12 websites for smarter travel

It can be hard to narrow down a destination. TripTuner calculates your preferences then matches you with an ideal destination.

Free meal aside, this is a great way to share homemade food while meeting locals and travelers.

Travelers can rent a piece of garden for "bamping" (basic camping) or add swimming pools, barbecues, Wi-Fi and babysitting service for a "glamping" (glamorous camping) experience.

This membership service offers high-end vacation homes for temporary guests. For owners, no chance of their homes being trashed by rowdies.

The days of multiple search tabs may be over. All The Rooms (still in development) searches hotels, bed and breakfasts, hostels and home rentals, then offers the best options on one screen.

From Harry Potter tours to sandcastle building, "hoppers" choose from more than 800 activities led by locals.

This site's map helps you avoid or seek out icebergs in Newfoundland and Labrador's Iceberg Alley.

Intervac Home Exchange can free up a lot of a travel budget. The annual fee grants you unlimited home swaps around the world.

Jet Lag Rooster calculates a personalized plan for combating jet lag. You'll need your own self control to fight those dreaded 10 a.m. "naps."

Roomer is like travel karma in website form. For helping out fellow travelers by selling off your unused rooms, you'll be rewarded with discounted hotel rates. Rooms in New York can be reduced to half price.

This seat guide helps steer you away from extra-cramped and oft-bumped into seats.

If you need to be productive while traveling, you can volunteer for chores at World Wide Opportunities on Organic Farms. The farms and vineyards will let you stay and eat in exchange for a few hours of work each day.

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• Intervac members get access to unlimited home swaps


• Iceberg Alley in Canada can be navigated with a tracking map at Iceberg Finder


• Meal Sharing connects world travelers and locals who want company for dinner


• Jet Lag Rooster computes personalized plans for combating jet lag

(CNN) -- Want a real home-cooked meal in a foreign country?

Got a burning desire to track icebergs in Canada?

Need to know how to build a proper sandcastle?

The best new travel sites offer these and other unique experiences.

Triptuner.com

TripTuner tries to find your ideal destination by matching travel to your tastes and preferences.

A panel of scales lets you choose the degree of experience you want: relaxing or active, bikini or parka, adult or kid-friendly, beach or mountain, urban or remote, high-end or thrifty, and everything in between.

High preference for "active" and "mountain" gets you to Mount Kilimanjaro, Torres del Paine in Chile or Innsbruck, Austria.

Maxing out "relaxing" and "bikini" matches you with Mykonos, Greece, and the Seychelles.

You can limit recommendations to a region closer to you, for your wallet's sake.

The site's soundboard tuner is fun to play with, but goes no further than booking hotel rooms.

Triptuner.com

Mealsharing.com

What better way to experience local cuisine than to eat with locals in their homes?

Meal Sharing brokers invitations to home cooked meals around the world.

It's not only easy on the wallet, it's a great way to meet fellow travelers and locals, rather than relying on restaurants or room service for every meal.

Mealsharing.com

Campinmygarden.com

Love the idea of camping, but can't give up a clean toilet?

Travelers can set up tents in the backyards of houses around the world from $5 per person a night.

The site's "glamping" options include swimming pools, barbecues, Wi-Fi and babysitting services.

"Bamping" (basic camping) options provide little more than a corner of turf with bathroom facilities.

Campinmygarden.com

Anyfriendofours.com

This home rental site takes "exclusive" seriously.

Applicants (both hosts and renters) must be second homeowners and approved by a membership board.

It helps to be recommended by an existing member.

Members have access to well-maintained homes in reliable locations.

Owners rest easy knowing their homes won't be trashed by rowdies.

Members can rent apartments in Florida for $75 a night or private villas in Mykonos for $1,600 a night.

Anyfriendofours.com

Alltherooms.com

The days of having Expedia, Kayak, Hotwire and Groupon opened on multiple tabs may be over.

All The Rooms is a search engine that trawls hotel sites, as well as alternative-stay sites such as Hostelworld, Airbnb and housetrip, combining research on hotels, hostels, bed and breakfasts, houses and apartments onto one page.

Alltherooms.com

MORE: Best home-exchange websites

Canaryhop.com

U.S. comedian Andy Samberg found himself wondering what to do while on a trip in France and shortly after co-founded CanaryHop.

With more than 800 activities offered by "canaries" (local guides) for "hoppers" (travelers), the site aims to keep travelers from twiddling their thumbs on vacation.

Popular trips include a Harry Potter overnight tour and a terracotta warriors tour.

Travelers can book quirky activities, like learning to build sandcastles, make bows and arrows or become gladiators.

Canaryhop.com

MORE: 20 funniest travel quotes you've never heard

Icebergfinder.com

The Titanic tragedy inspired the formation of the International Ice Patrol, an aerial surveillance of icebergs.

Visitors to Canada's east coast can use Iceberg Finder's interactive map to track -- or avoid -- the glacial giants.

Iceberg sightings are usually between April and June.

Icebergfinder.com

Intervac-homeexchange.com

Accommodations can take up a large chunk of a travel budget, money better spent on shopping, eating, drinking or upgrading your souvenir purchases.

MORE: 15 biggest souvenir-buying no-no's

For an annual fee of €70 ($95), travelers get access to unlimited home exchanges.

Swappers can choose stays by location, such as "in the city," "by the sea" or "in the mountains."

Intervac-homeexchange.com

Jetlagrooster.com

This website helps you sleep.

Even the nicest hotel room can become stale when you're suffering jet lag.

Launched last year by Jay Olson of Canada's Simon Fraser University, Jet Lag Rooster helps travelers shift body clocks by adjusting their exposure to light.

The site uses trip details and usual sleep patterns to calculate a battle plan against jet lag.

Jetlagrooster.com

MORE: Exercise, alcohol, Viagra -- the new "best cures" for jet lag

Roomertravel.com

Canceled travel plans waste money.

Paying for the hotel room you can't use adds to the misery.

Roomer helps you sell off un-used hotel reservations.

You can set your own prices to earn back some of the room rate or cancellation fee.

Deal seekers can often pick up unwanted rooms at a fraction of the listed price.

Roomertravel.com

MORE: 15 bizarre, unique hotels

Seatguru.com

For many of us, being cramped on a plane is as close as this world gets to Hell.

A little extra leg room and space by a window can make a flight almost tolerable.

SeatGuru points out preferred spots on all models of planes, as well as seats of misery, like those too close to the bathroom, those with limited leg room and recline, those often bumped by aisle walkers and even those that have an uneven alignment of TV and window.

There are also seat tips for first- and business-class fliers.

Seatguru.com

MORE: World's best economy class is ...

Wwoof.com

Plonk yourself down at these places.

Volunteers are given food and accommodation in exchange for helping out with day-to-day chores for four to six hours on a farm or vineyard.

Some hosts have multiple volunteers you can connect with.

This is a cheap idea for wine lovers who might pay thousands of dollars for a high-end vineyard stay.

Depending on the WWOOF (Worldwide Opportunities on Organic Farms) organization, membership fees vary.

Wwoof.net

A terror group too brutal for al Qaeda?

Medical personnel look for survivors after a reported airstrike in Aleppo, Syria, on Saturday, February 1. The United Nations estimates more than 100,000 people have been killed since the Syrian conflict began in March 2011. Click through to see the most compelling images taken during the conflict, which is now a civil war:

Syrians carry a dead body following an airstrike on February 1.

A man walks amid debris and dust on January 31.

An injured man is covered in dust after an airstrike on January 29.

A man tries to fix electrical wires in a neighborhood of Aleppo, Syria, on January 27.

Rebels and civilians check out a crater that activists say resulted from a Syrian government airstrike on an Aleppo bus station on Tuesday, January 21.

Men rush to a site that Syrian government forces reportedly hit in Aleppo on January 21.

Buildings lie in ruins in Aleppo on Sunday, January 19, after reported air raids by Syrian government planes.

A Syrian child collects items from a garbage pile on Saturday, January 18, in Douma, northeast of the capital.

A piece of exploded mortar lies in a street in Daraya, a city southwest of Damascus, on Friday, January 17.

Residents search for survivors in Aleppo on Saturday, December 28, 2013, after what activists said were airstrikes by forces loyal to Syrian President Bashar al-Assad.

A man appears distraught after an air raid in Aleppo on Monday, December 23.

Free Syrian Army fighters sit in a damaged house in Old Aleppo on Saturday, December 21.

People search for survivors amid the rubble after an airstrike in Aleppo on Tuesday, December 17.

A man sits on the ground after the airstrike in Aleppo on December 17.

A woman carries children following airstrikes on a rebel area of Aleppo on Sunday, December 15.

Syrians look at the aftermath of an airstrike on a rebel area of Aleppo on December 15.

Syrians help a wounded woman following airstrikes in Aleppo on December 15.

Syrians look at the aftermath of an airstrike on a rebel area of Aleppo on December 15.

Syrian rebel fighters clash with pro-government forces in Aleppo on Wednesday, December 11.

A woman weeps inside a damaged vehicle after forces loyal to President Bashar al-Assad captured the town of Nabak on Monday, December 9.

A rebel fighter takes position during fighting with government forces in Deir Ezzor on Monday, December 2.

Shiite fighters from a group called the Hussein Brigade search for rebels from the Free Syrian Army in Hejeira on Thursday, November 21.

Free Syrian Army rebels battle government forces in Aleppo on Monday, November 18.

A rebel fighter holds his position in a damaged building during clashes with government forces in Deir Ezzor on Monday, November 11.

A rebel fighter fires during clashes with government forces in Deir Ezzor on November 11.

A rebel fighter prepares an improvised mortar shell in Aleppo, Syria, on Saturday, November 9.

Two injured men are transported on a cart in Aleppo, Syria, following shelling as fighting between pro-government forces and rebels continues on Saturday, October 26.

Rebel fighters hold a position in Deir Ezzor, Syria, on Thursday, October 24.

An opposition fighter stands in the doorway of a building as he smokes a cigarette in Deir Ezzor, Syria, on Tuesday, October 22.

People use buckets as they try to extinguish a fire that ignited at a fuel station in Aleppo, Syria, on Sunday, October 20.

A Syrian opposition fighter aims a catapult toward regime forces in Aleppo, Syria, on Thursday, October 17.

Firefighters extinguish a burning vehicle after two mortar rounds struck the Abu Roumaneh area in Damascus, Syria, on Saturday, October 12.

An opposition fighter aims as others run for cover while they hold a position behind burning tires in the Salaheddin district of the northern Syrian city of Aleppo on Wednesday, October 9.

An opposition fighter smokes a cigarette as he takes a break following the injury of his friend in the Salaheddin neighborhood of Aleppo on October 9.

Smoke rises after a mortar shell hit a residential area during fighting between Syrian government forces and rebels in Maaret al-Numan, Syria, on October, 9.

Rebel fighters cover a car in mud for camouflage at an undisclosed location in Syria's northwestern province of Idlib on Tuesday, October 8.

Masked female rebel fighters walk alongside their trainer on a street in the Salaheddin district of Aleppo, Syria, on October 8.

A rebel fighter prays moments before heading into battle in Maaret al-Numan, Syria, on Monday, October 7.

A mother comforts her baby in an area where she and her family have taken shelter after fleeing their village turned battlefield in Syria's Idlib province on Sunday, September 22.

A man checks an AK-47 at his gun shop in Aleppo, Syria, on Saturday, September 21.

Free Syrian Army fighters take cover moments after firing a rocket toward government forces in the Idlib province of northern Syria on Friday, September 20.

Rebel fighters inspect a stairwell amid fighting against Syrian government forces on Thursday, September 19, in the Saif al-Dawla district of Aleppo, Syria.

A Syrian child sits in a village in the Idlib province countryside on Septeptember 19.

Opposition fighters react after returning from the battlefield in the Idlib province countryside on September 19.

Smoke rises after a bomb was thrown from a helicopter, hitting a rebel position during heavy fighting between troops loyal to Syrian President Bashar al-Assad and opposition fighters in the Idlib province on September 19.

Rebel fighters duck behind a barricade from firing in Aleppo on Wednesday, September 18.

AFP reporter Sammy Ketz hits the ground as a Syrian soldier runs past during sniper fire in Maalula on September 18. Ketz and a photographer were reporting on the ancient Christian Syrian town northeast of Damascus.

A Syrian opposition fighter takes a break on a mountain near a rebel camp in Idlib province on September 18.

A Free Syrian Army fighter rests inside a cave at a rebel camp in Idlib province on Tuesday, September 17.

Volunteers wear protective gear to show a class how to respond to a chemical attack in Aleppo, Syria, on September 15. For two months, Mohammad Zayed, an Aleppo University student, has been training a group of 26 civilians to respond to a chemical attack.

Syria's pro-Assad militia rest near Maalula, Syria, on Friday, September 13.

Syrian soldiers take aim at rebel fighters positioned in the mountains of the Christian town of Maalula on September 13.

Rebels parade at a former military academy north of Aleppo during a September 13 ceremony to mark an agreement to unite two rebel brigade forces.

A fighter of the Popular Front for the Liberation of Palestine General Command squats next to the covered body of an alleged foreign rebel fighter in the Yarmouk refugee camp in the Syrian capital of Damascus on Thursday, September 12.

An opposition fighter runs in front of a sniper curtain in the industrial area of Deir Ezzor, Syria, during clashes with regime forces on September 12.

A sheet hangs across an alley way to shield fighters from sniper fire as a fighter of the Popular Front for the Liberation of Palestine General Command walks past destroyed buildings in the Yarmouk refugee camp in Damascus, Syria, on September 12.

A Free Syrian Army fighter stands guard inside a damaged house in Aleppo's Qastal al-Harami neighborhood on September 11.

Free Syrian Army fighters climb a flight of stairs to take positions near the Hanano barracks on September 11.

A Syrian government tank is seen during clashes with Free Syrian Army fighters in Maaloula, Syria, on September 11.

A funeral is held on September 11 for three Christian Syrians killed during battles with an al Qaeda-linked rebel group that took control of the historic Christian town of Maaloula from regime forces during the weekend.

A man walks through a destroyed residential area of Saraqib, Syria, on Monday, September 9, following repeated airstrikes by government forces.

A soldier wears a picture of Syrian President Bashar al-Assad on his chest while at a market in old Damascus on September 8.

A Free Syrian Army fighter prays in a trench in the Damascus suburbs on September 8.

A Free Syrian Army fighter takes up a shooting position in Aleppo on September 8.

A Free Syrian Army fighter runs for cover in Raqqa province on September 8.

Buildings are heavily damaged in the Salah al-Din area of Aleppo on September 8.

A boy named Issa, 10, carries a mortar shell in a weapons factory of the Free Syrian Army in Aleppo on Saturday, September 7. The boy works with his father in the factory.

Issa fixes a mortar launcher in the Aleppo weapons factory on September 7.

A bedroom lies in ruins after clashes between government forces and rebels around Ariha on September 7.

Syrian forces are seen in the Syrian Christian town of Maaloula on September 7.

A Syrian soldier prepares large-caliber bullets for a machine gun in Maaloula on September 7.

A man stands inside a home damaged by heavy shelling in Arbeen, a suburb of Damascus, Syria, on September 7.

Men gather on the remains of a destroyed building after reported airstrikes by Syrian government forces in the rebel-held northwestern Syrian province of Idlib on Thursday, September 5.

A Free Syrian Army fighter takes cover as he watches forces loyal to President Bashar al-Assad near Hanano barracks in Aleppo on September 3.

Free Syrian Army fighters walk inside a damaged house in Aleppo on September 3.

Free Syrian Army fighters talk inside a burnt house in Aleppo on September 3.

A Free Syrian Army fighter peeks through the curtains of a bedroom in Deir ez-Zor, Syria, on Monday, September 2.

Free Syrian Army fighters take their positions behind piled sandbags, as one of them points his weapon, in Deir ez-Zor on September 2.

A rebel fighter points his weapon at Syrian regime forces in Deir ez-Zor on September 2.

Syrian firefighters try to extinguish a fire after a missile hit a residential building in Damascus, Syria, on September 2.

A U.N. arms expert collects samples during an inspection of a suspected chemical weapons strike site in the Ghouta area outside Damascus on August 29.

People search for belongings in rubble in Raqqa, Syria, on August 29.

Free Syrian Army fighters launch a rocket toward forces loyal to Syrian President Bashar al-Assad in Deir Ezzor on August 29.

A Syrian Kurd uses hay to hide another woman in a training session organized by the Kurdish Women's Defense Units on Wednesday, August 28, in a northern Syrian border village. They're preparing if the area comes under attack.

Free Syrian Army fighters escort U.N. vehicles with chemical weapons experts on August 28 through a site of a suspected chemical weapons attack outside Damascus.

A Free Syrian Army fighter takes position behind sandbags in the old city of Aleppo, Syria, on Tuesday, August 27.

A U.N. team leaves its Damascus, Syria, hotel in a convoy on Monday, August 26. The team was to investigate an alleged chemical attack that killed hundreds last week in a suburb of the Syrian capital. Sniper fire hit a vehicle used by the U.N. chemical weapons investigation team multiple times Monday, according to the United Nations.

A Syrian soldier walks down a street in Damascus on Saturday, August 24.

Pigeons lie dead on the ground on August 24 from after what activists say is the use of chemical weapons by government forces in the Damascus suburb of Arbeen.

Columns of smoke rise in Barzeh after heavy shelling on Friday, August 23.

A young Free Syrian Army fighter is reflected in a mirror as he takes position in a house in Aleppo on Thursday, August 22.

Rebels move around a building in Aleppo on August 22.

Syrian rebels claim pro-government forces used chemical weapons to kill citizens outside Damascus on Wednesday, August 21. People inspect bodies in this photo released by the Syrian opposition Shaam News Network.

People search the rubble of a bombed building in Aleppo, Syria, on Friday, August 16.

Men bury the bodies of six members of the same family killed in a bombing in Raqqa on Saturday, August 10.

Syrian Army soldiers patrol a devastated street in Homs on Wednesday, July 31.

Free Syrian Army fighters move through a hole in a wall in Khan al-Assal on Monday, July 22, after seizing the town.

A rebel fighter walks past swings in a deserted playground in Deir al-Zor, Syria, on Sunday, July 21.

A rebel fighter speaks with a fellow fighter through a hole in a wall in Deir al-Zor on July 21.

A Free Syrian Army fighter casts a shadow on a wall as he carries his weapon in a shelter in Deir al-Zor on Thursday, July 18.

Yahya Sweed, 13, is comforted by his father as he lies on a bed in Kfar Nubul on Tuesday, July 16. The boy was injured by shrapnel, resulting in the amputation of his right leg.

A rebel fighter naps in a trench about 300 feet from the Syrian government forces' positions along the highway connecting Idlib with Latakia on Monday, July 15.

A rebel fighter uses a hole in the wall of a destroyed school to aim at Syrian government forces in the Izaa district of Aleppo on Sunday, July 14.

A Free Syrian Army fighter uses a mirror to scope out snipers loyal to Syrian President Bashar al-Assad in Aleppo on Friday, July 12.

A Free Syrian Army fighter stands over a boy who was injured during shelling in Al-Bara on Monday, July 8.

Members of the Free Syrian Army fire a homemade rocket toward regime forces in Deir al-Zor on Sunday, June 16.

Syrian rebels leave their position in the northwestern town of Maaret al-Numan on Thursday, June 13. The White House said that the Syrian government has crossed a "red line" with its use of chemical weapons and announced it would start arming the rebels.

Forces loyal to Syrian President Bashar al-Assad are seen near Qusayr on Thursday, May 30.

Syrian rebels take position in a house during clashes with regime forces in the old city of Aleppo on May 22.

Syrian army soldiers take control of the village of Western Dumayna north of the rebel-held city of Qusayr on Monday, May 13. Syrian troops captured three villages in Homs province, allowing them to cut supply lines to rebels inside Qusayr town, a military officer told AFP.

Rebel fighters fire at government forces in the northern Syrian city of Aleppo on Sunday, May 12.

Searchers use a flashlight as they look for survivors among the rubble created by what activists say was a missile attack from the Syrian regime, in Raqqa province, Syria, on April 25.

A Kurdish fighter from the "Popular Protection Units" (YPG) takes position inside a building in the majority-Kurdish Sheikh Maqsood area of Aleppo, on Apri. 21.

People walk past destroyed houses in the northern Syrian town of Azaz on Sunday, April 21.

Free Syrian Army fighters take positions prior to an offensive against government forces in the Khan al-Assal area, near Aleppo on Saturday, April 20.

Men inspect damage at a house destroyed in an airstrike in Aleppo on April 15.

Syrian and Kurdish rebel fighters walk in the Sheikh Maqsud district of Aleppo on April 14.

A female rebel monitors the movement of Syrian government forces in Aleppo's Sheikh Maqsud neighborhood on Thursday, April 11.

A rebel runs to avoid sniper fire from Syrian government forces in Aleppo on April 11.

Syrian rebels observe the movement of Syrian government forces around Al-Kendi hospital in Aleppo on Wednesday, April 10.

Rescue teams and security forces check out the scene of a deadly car bomb explosion in Damascus on April 8.

The fighting has taken a toll on buildings in Aleppo's Saladin district, seen here on April 8.

A Syrian rebel runs for cover in Deir ez-Zor on April 2.

A rebel checks for snipers across the street toward the Citadel in Aleppo, Syria, on Saturday, March 30, in this photo taken by iReporter Lee Harper.

A Free Syrian fighter mourns the death of a friend in Aleppo on March 30, in this photo taken by iReporter Lee Harper.

A Syrian opposition fighter runs for cover from Syrian army snipers in Aleppo on Wednesday, March 27.

A Syrian girl covers her face to protect herself from fumes as a street covered with uncollected garbage is fumigated in Aleppo on Sunday, March 24.

A Syrian man and his family drive past damaged buildings in Maarat al-Numan, on Wednesday, March 20.

Syrians carry the body of a Syrian army soldier during a funeral ceremony in Idlib province on Tuesday, March 19.

Syrian rebels take position in Aleppo, the largest city in the country, on March 11.

Syrian men search for their relatives amongst the bodies of civilians executed and dumped in the Quweiq River on March 11.

A Free Syrian Army fighter looks back as smoke rises during fighting between rebel fighters and forces loyal to Syria's President Bashar al-Assad on the outskirts of Aleppo on Saturday, March 2.

Residents read Shaam News newspapers published by the Free Syrian Army in Aleppo on March 2.

A member of the Free Syrian Army reacts to the death of a comrade who was killed in fighting, at Bustan al Qasr cemetery in Aleppo on Friday, March 1.

A rebel fighter throws a home-made grenade at Syrian government forces in Aleppo on February 16.

A member of the Free Syrian Army stands with his weapon as he looks at a rainbow in Aleppo on February 16.

A Syrian woman looks through a bus window in Aleppo on February 14.

Free Syrian Army fighters walk through a dust-filled stairwell in Damascus on February 7.

A Syrian rebel gestures at comrades from inside a broken armored personnel carrier in Al-Yaqubia on February 6.

A rebel fighter throws a hand grenade inside a Syrian Army base in Damascus on February 3.

People stand in the dust of a building destroyed in an airstrike in Aleppo, Syria on February 3.

Free Syrian Army fighters run as they enter a Syrian Army base during heavy fighting in the Arabeen neighborhood of Damascus on February 3.

An unexploded mortar shell fired by the Syrian Army sits lodged in the ground in Damascus on January 25.

Fighters from Fateh al Sham unit of the Free Syrian Army fire on Syrian Army soldiers at a check point in Damascus on January 20.

A Free Syrian Army fighter walks between buildings damaged during Syrian Air Force strikes in Damascus on January 19.

A Syrian rebel fighter tries to locate a government jet fighter in Aleppo on January 18.

Syrian rebels launch a missile near the Abu Baker brigade in Albab on January 16.

A Syrian boy walks near rubbish next to tents at a refugee camp near the northern city of Azaz on the Syria-Turkey border, on January 8.

Syrians look for survivors amid the rubble of a building targeted by a missile in Aleppo on January 7.

A father reacts after hearing of a shelling by forces loyal to Syria's President Bashar al-Assad in Aleppo on January 3.

A patient smokes a cigarette at Dar Al-Ajaza psychiatric hospital in Aleppo on December 18, 2012. The psychiatric ward, housing around 60 patients, has lacked the means to function properly since fighting broke out there in July.

Syrians mourn a fallen rebel fighter at a rebel base in the al-Fardos area of Aleppo on December 8, 2012.

Members of Liwa (Brigade) Salahadin, a Kurdish military unit fighting alongside rebel fighters, monitor the area in the besieged district of Karmel al-Jabl in Aleppo on December 6, 2012.

A member of Liwa Salahadin aims at a regime fighter in the besieged district of Karmel al-Jabl in Aleppo on December 6, 2012.

Two young boys sit underneath a washline in a refugee camp on the border between Syria and Turkey near Azaz on December 5, 2012.

The bodies of three children, who were allegedly killed in a mortar shell attack that landed close to a bakery in Aleppo, on December 2, 2012, are laid out for identification by family members at a makeshift hospital at an undisclosed location of the city.

Smoke rises in the Hanano and Bustan al-Basha districts in Aleppo on December 1, 2012 as fighting continues through the night.

Damaged houses in Aleppo are seen after an airstrike on November 29, 2012.

A Syrian rebel mourns the death of a comrade in Maraat al-Numan on November 20, 2012.

Syrians protesters stand on Assad's portrait during an anti-regime demonstration in Aleppo on November 16, 2012.

A Syrian rebel takes cover during fighting against Syrian government forces in Aleppo on November 15, 2012.

Syrian opposition fighter Bazel Araj, 19, sleeps next to his pistol in Aleppo on November 11, 2012.

A rebel fighter fires at a Syrian government position in Aleppo on November 6, 2012.

A Syrian rebel leaps over debris left in the street while running across a "sniper alley" near the Salahudeen district in Aleppo on November 4, 2012.

Rebels hold their position in the midst of a battle on November 3, 2012 in Aleppo.

A man cries while being treated in a local hospital in a rebel-controlled area of Aleppo on October 31, 2012.

A man is treated for wounds after a government jet attacked the Karm al-Aser neighborhood in eastern Aleppo on October 31, 2012.

A Syrian rebel interrogates a handcuffed and blindfolded man suspected of being a pro-regime militiaman in Aleppo on October 26, 2012.

Smoke rises from a fuel station following a mortar attack as Syrian women walk on a rainy day in the Arqub neighborhood of Aleppo on October 25, 2012.

A Syrian rebel fires at an army position in the Karm al-Jabal district of Aleppo on October 22, 2012.

A wounded Syrian boy sits on the back of a truck carrying victims and wounded people to a hospital following an attack by regime forces in Aleppo on October 21, 2012.

A man lies on the ground after being shot by a sniper for a second time as he waits to be rescued by members of the Al-Baraa Bin Malek Battalion, part of the Free Syria Army's Al-Fatah brigade, in Aleppo on October 20, 2012.

Syrian army soldiers run for cover during clashes with rebel fighters at Karam al-Jabal neighborhood of Aleppo on October 20, 2012.

Smoke rises after a Syrian Air Force fighter jet fired missiles at the suburbs of the northern province of Idlib on October 16, 2012.

A Syrian opposition fighter stands near a post in Aleppo on October 11, 2012.

A Syrian man mourns the death of his father, who was killed during a government attack in Aleppo on October 10, 2012.

A rebel fighter is carried by his friends and laid on a gurney to be treated for gunshot wounds sustained during heavy battles with government forces in Aleppo on October 1, 2012.

Syrian rebels help a wounded comrade to an Aleppo hospital after he was injured in a Syrian army strike on September 18, 2012.

Free Syria Army fighters are reflected in a mirror they use to see a Syrian Army post only 50 meters away in Aleppo on September 16, 2012.

A Syrian man carrying grocery bags tries to dodge sniper fire as he runs through an alley near a checkpoint manned by the Free Syria Army in Aleppo on September 14, 2012.

A woman walks past a destroyed building in Aleppo on September 13, 2012.

Free Syrian Army fighters battle during street fighting against Syrian army soldiers in Aleppo on September 8, 2012.

A Syrian man wounded by shelling sits on a chair outside a closed shop in Aleppo on September 4, 2012.

A woman sits in her wheelchair next to her house, damaged by a Syrian air raid, near Homs on August 26, 2012.

Members of the Free Syrian Army clash with Syrian army soliders in Aleppo's Saif al-Dawla district on August 22, 2012.

A man mourns in front of a field hospital on August 21, 2012 in Aleppo.

Wounded civilians wait in a field hospital after an air strike on August 21, 2012 in Aleppo.

People pray during the funeral of a Free Syrian Army fighter, Amar Ali Amero, on August 21, 2012.

A man cries near the graves of his two children killed during a recent Syrian airstrike in Azaz on August 20, 2012.

A Syrian woman holds her dead baby as she screams upon seeing her husband's body being covered following an airstrike by regime forces on the town of Azaz on August 15, 2012.

A Syrian rebel runs in a street of Selehattin during an attack on the municipal building on July 23, 2012.

Syrian rebels hunt for snipers after attacking the municipality building in the city center of Selehattin on July 23, 2012.

Members of the Free Syrian Army's Mugaweer (commandos) Brigade pay their respects in a cemetery on May 12, 2012 in Qusayr.

Syrian rebels take position near Qusayr on May 10, 2012.

A Free Syrian Army member takes cover in underground caves in Sarmin on April 9, 2012.

Rebels prepare to engage government tanks that advanced into Saraquib on April 9, 2012.

Men say prayers during a ceremony in Binnish on April 9, 2012.

A young boy plays with a toy gun in Binnish on April 9, 2012.

A Free Syrian Army rebel mounts his horse in the Al-Shatouria village near the Turkish border in northwestern Syria on March 16, 2012, a year after the uprising began.

Syrian refugees walk across a field before crossing into Turkey on March 14, 2012.

A rebel takes position in Al-Qsair on January 27, 2012.

A protester in Homs throws a tear gas bomb back towards security forces, on December 27, 2011.

A man stands under a giant Syrian flag outside the Umayyad Mosque in Damascus on December 24, 2011.

A member of the Free Syrian Army looks out over a valley in the village of Ain al-Baida on December 15, 2011.

Members of the Free Syrian Army stand in an valley near the village of Ain al-Baida, close to the Turkish border, on December 15, 2011.

Displaced Syrian refugees walk through an orchard adjacent to Syria's northern border with Turkey on June 14, 2011, near Khirbet al-Jouz.

A Syrian man holds up a portrait of President Bashar al-Assad during a rally to show support for the president in Damascus on April 30, 2011.

Syrians rally to show their support for President Bashar al-Assad in Damascus on April 30, 2011.

A screen grab from YouTube shows thick smoke rising above as Syrian anti-government protesters demonstrate in Moaret Al-Noman on April 29, 2011.

A screen grab from YouTube shows Syrian anti-government protesters run for cover from tear gas fired by security forces in Damascus on April 29, 2011, during the "Day of Rage" demonstrations called by activists to put pressure on al-Assad.

A woman sits by the hospital bed of a man allegedly injured when an armed group seized rooftops in Latakia on March 27, 2011, and opened fire at passers-by, citizens and security forces personnel according to official sources.

Syrians wave their national flag and hold portraits of al-Assad during a rally to show their support for their leader in Damascus on March 29, 2011.

Syrian protesters chant slogans in support of al-Assad during a rally in Damascus on March 25, 2011.

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• A Syrian rebel group has been disowned by al Qaeda


• Peter Bergen says al Qaeda's central leadership seems put off by the group's brutality


• The split could weaken al Qaeda's grip in Syria, after it made advances there, he says


• Bergen: U.S. officials believe more Americans have gone to fight vs. the Syrian regime

Editor's note: Peter Bergen is CNN's national security analyst, a director at the New America Foundation and the author of "Manhunt: The Ten-Year Search for bin Laden -- From 9/11 to Abbottabad."

(CNN) -- When even al Qaeda publicly rejects you because you are too brutal, it's likely a reasonable indicator that you are.

A long simmering dispute between "al Qaeda Central," headed by Ayman al-Zawahiri, and the most brutal al Qaeda affiliate in Syria, generally known as the Islamic State of Iraq and Syria, surfaced publicly on Monday.

On jihadist websites, al Qaeda's central leadership posted a notice saying ISIS "is not a branch of the al Qaeda group."

It is the first time in its quarter century history that al Qaeda has officially rejected one of its affiliates.

Why did this happen? ISIS and another al Qaeda affiliate known as the Nusra Front have been fighting each other in Syria for several weeks now.

This open warfare caps a dispute between ISIS and Nusra about who is boss in Syria that has been brewing since ISIS released a statement in April announcing its official merger with Nusra.

A leader of Nusra rejected the merger, and in June, al-Zawahiri annulled the merger. ISIS, in turn, rejected al-Zawahiri's annulment of the merger.

Al-Zawahiri is clearly fed up with ISIS's open rejection of his overall leadership of the al Qaeda network. Moreover, he is likely quite concerned about how ISIS is alienating ordinary Syrians by a brutal campaign that has involved the public beheading of opponents and the imposition of Taliban-style rule on the population, including the banning of smoking, music and unveiled women in public.

Al Qaeda's leader has seen this movie before -- in western Iraq in 2006, when al Qaeda in Iraq (the parent organization of ISIS) imposed a brutal Taliban-like rule on the population that caused the Sunni tribes in western Iraq to rebel against al Qaeda in an uprising known as "the Sunni Awakening."

The Sunni Awakening, with a heavy assist from the U.S. military, led to al Qaeda losing control of much of western Iraq by 2008.

Nusra seems to have learned from the mistakes of al Qaeda in Iraq and is not imposing Taliban-style rule in the areas of Syria that it controls and is instead operating in a Hezbollah-like manner, providing social services. The group, for instance, provides bread and electricity in the eastern Syrian city of Ash Shaddadi, where it also controls the city's wheat silos and oil wells.

Al Qaeda 'disowns' affiliate, 'a PR move'

Regional players role in Syrian peace

Teenage refugee won't give up on Syria

Nursa also is engaging in the kind of alliance-building that al Qaeda affiliates generally have not been able to pull off because they regard compromise as a deviation from their God-given beliefs. Nusra has, for instance, allied with more moderate elements of the Syrian opposition to fight against ISIS during the past several weeks.

Nusra, in fact, represents what al Qaeda's core leadership wants in one of its affiliates: A group that doesn't tarnish the al Qaeda brand by using brutal tactics against fellow Muslims.

This has been a core concern for al Qaeda for the past decade. Al-Zawahiri sent a letter to al Qaeda in Iraq in the summer of 2005 admonishing the group against its campaign of killing Shia civilians.

Similarly, Osama bin Laden wrote a private letter to the al Qaeda-aligned Somali terrorist group, Al-Shabaab, in 2010 telling the organization to stop attacking in the central market of the Somalia capital, Mogadishu, because such attacks were killing Muslim civilians.

Also in 2010, al Qaeda leaders wrote a private letter to the leader of the Pakistan Taliban telling him forcefully to suspend his group's campaign of attacks against mosques and markets, which was killing hundreds of Pakistani civilians.

The difference now is that al Qaeda has gone public with its displeasure with ISIS and is also officially cutting the group off.

Despite the bitter differences between the two al Qaeda-aligned groups in Syria, senior U.S. counterterrorism officials tell me they are "All Syria. All the time."

That is because al Qaeda affiliated groups in Syria and neighboring Iraq now control more territory in the Arab world than at any time in their history; a swath of land that runs from northwestern Syria some 400 miles to the east into western Iraq.

On Tuesday, CIA Director John Brennan testified before the House Intelligence Committee: "There are camps inside of both Iraq and Syria that are used by al Qaeda to develop capabilities that are applicable, both in the theater, as well as beyond." Brennan asserted that these camps represent a real threat to the United States.

Adding to their concerns, U.S. counterterrorism officials tell me that more Americans have traveled to fight in Syria than was previously understood. They believe some 70 Americans have fought there over the past three years. Previous estimates suggested only a handful of Americans had done so.

U.S. counterterrorism officials are rightly concerned that Americans who have fought in Syria will return to the States radicalized and perhaps even to plan to carry out terrorist attacks.

That said, it isn't clear how many of the 70 Americans who are estimated to have fought in Syria have done so alongside the al Qaeda-aligned groups or with other more moderate rebel groups who are fighting the Bashar al-Assad regime with some degree of American support.

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