The FBI this week published pictures of three men it says may have played a role in an attack last year on the U.S. consulate in Benghazi, Libya. U.S. Ambassador to Libya Chris Stevens and three members of his staff died in the attack.
A U.S. law enforcement official told CNN on condition of anonymity that "three or four members of al-Qaida in the Arabian Peninsula," the Yemeni branch of al-Qaida, may have played a role in the attack.
CNN said several sources said that some of the attackers were Yemeni men. CNN reported that it couldn't make a connection between what its sources said and the pictures released by the FBI.
AQAP is said to have inspired acts of domestic terrorism in the United States, including shootings at Fort Hood, Texas, in 2009.
Attacks on Benghazi have been a source of contention for U.S. lawmakers. U.S. Secretary of State John Kerry, and former Secretary Hillary Clinton, faced tough questions from policymakers concerned about security for diplomatic posts overseas.
The French Embassy in Tripoli was bombed last month. A British condemnation of that attack warned that travel to Benghazi wasn't advised under any circumstances.