The head of Libya\'s national assembly Friday blamed Al-Qaeda for an attack on the U.S. consulate in the city of Benghazi that killed ambassador Chris Stevens and three other Americans. Mohammed al-Megarif laid a bouquet of flowers in front of the consulate where Stevens died Tuesday when suspected Islamic militants fired on the compound with rocket-propelled grenades and set it ablaze. Visibly moved, the General National Congress president said he regretted the loss of \"a friend of Libyans who rendered laudable services to Libya.\" Surrounded by heavy security, Megarif was accompanied by Libya\'s military chief of staff Yussef al-Mangush. U.S. officials are investigating the possibility that the assault was an Al-Qaeda-linked plot using a protest against an anti-Islam film as cover to mark the anniversary of the September 11, 2001 attacks on the United States. Megarif pointed a finger at the militant group. \"The film was made six months ago. How can you explain that this incident coincided with September 11. We mustn\'t lie to ourselves,\" he told AFP, without naming Al-Qaeda. In the immediate aftermath of the attack, Megarif had blamed the attack on both Al-Qaeda elements and remnants of Moamer Kadhafi\'s regime which was toppled last year in a brutal conflict.