American killed in Saudi shooting

• NEW: Suspected gunman had worked at the same company as the victims


• NEW: He was recently dismissed "due to drug related issues," embassy says


• The shooting happened in Saudi Arabia's capital, Riyadh


• No information on a motive has been immediately released

(CNN) -- One American defense contract worker was killed and another was lightly injured in a shooting at a gas station in Saudi Arabia's capital on Tuesday, a U.S. State Department official said.

The two were at a gas station in Riyadh when a gunman opened fire on their car, the country's official news agency reported, citing police in the city.

The Saudi Embassy in the United States identified the suspected gunman as Abdulaziz Fahad Abdulaziz Alrashid, 24, a dual Saudi-American citizen who had worked at the same U.S. defense contractor as the victims.

He was recently dismissed from the job "due to drug related issues," the Embassy said.

Alrashid was reportedly taken into custody following a shootout with security forces, which left him injured.

Neither the Americans' names nor information about a possible motive was immediately released. The injured American was taken to a hospital, the Saudi Press Agency reported.

The Americans worked for Vinnell Arabia, a U.S. defense contractor supporting the Saudi Arabia National Guard, and were about a half-mile from a Vinnell base when the shooting happened, the State Department official said.

Vinnell Arabia, partly owned by U.S.-based Northup Grumman Corp., has helped to train Saudi national guard troops since 1975. It says it has more than 1,250 employees, some of whom are former U.S. troops. More than half of the employees are Saudis, the company says on its website.

CNN's Schams Elwazer contributed to this report.