Rebels: We captured general

• Gen. Rubén Darío Alzate was captured over the weekend


• Colombia's President has suspended peace talks with FARC rebels over the matter


• FARC leaders say they gained a valuable prize by capturing the general

Havana, Cuba (CNN) -- Why was a Colombian army general traveling deep in rebel territory, out of uniform and without bodyguards?

That country's largest guerrilla group Tuesday confirmed capturing Gen. Rubén Darío Alzate. The announcement came during a news conference in Havana, where guerrillas and Colombian government officials have been holding peace talks.

Both Colombian government officials and rebel leaders said they did not know what Alzate was doing in a remote area of western Colombia when guerrillas captured him over the weekend.

Colombian media reported he was the highest-ranking officer to be taken prisoner during the country's blood, five-decades-old civil war.

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Alzate commands a 2,500-soldier counterinsurgency group and previously headed the army's anti-kidnapping unit.

Leaders of the Revolutionary Armed Forces of Colombia, known as FARC, said they gained a valuable prize by taking Alzate prisoner.

"We are talking about a general who is one of the most important generals to their concept of counter-insurgency," the FARC leader known as Pablo Catatumbo said at the news conference Tuesday.

On Monday, Colombian President Juan Manuel Santos suspended the peace talks and demanded that FARC release Alzate immediately. Santos also called on the country's military to investigate why Alzate had apparently broken protocol by venturing into rebel territory.

According to Colombian government officials, Alzate was traveling by a boat along a river in an area known to be a hub for drug smugglers and rebels when he, an Army lawyer and a corporal were captured. A second soldier traveling with the group managed to escape and told officials that Alzate and his companions had been in the area to inspect an energy project.

But on Tuesday, FARC leaders said no such project exists in that area and that they were also baffled what Alzate's presence there. FARC leaders would not say whether they would free Alzate so that the peace talks could continue.

"We are willing to find a prompt, calm and just solution to this problem," said Catatumbo.

The U.S. government has provided Colombia's military with billions of dollars in training and aid to battle FARC guerrillas, who authorities accuse of massive-scale drug trafficking to finance their insurgency.

At the beginning of the peace talks in 2012, FARC leaders said they had released all their prisoners and hostages as a sign of good faith. But President Santos has resisted their offers of a ceasefire, saying a previous armistice allowed rebels to seize large swathes of territory.