A file photo of U.S. envoy Chris Stevens who was killed in an attack on the U.S. consulate in the eastern city of Benghazi by protesters angry over a film that ridiculed Islam's Prophet Muhammad.

Tripoli - Libyan authorities on Wednesday pointed a finger of blame at supporters of ousted leader Muammar Gaddafi's regime and at Al-Qaeda for a deadly attack on the US consulate in the eastern city of Benghazi.

“What happened yesterday coincided with September 11 and has a clear significance,” Mohamed al-Megaryef, president of Libya's highest political authority, the elected General National Congress, told reporters in Tripoli.

He was referring to Al-Qaeda's devastating attacks on the United States of September 11, 2001.

“We categorically refuse to allow our lands to be used to mount cowardly and dirty revenge attacks,” he said.

Washington's envoy to Libya and three other Americans were killed when an armed mob outraged over a low-budget movie mocking Islam late on Tuesday attacked the American consulate in Benghazi with rocket-propelled grenades.

Megaryef also pointed a finger of blame at the ousted regime, saying such actions were aimed at sabotaging Libya's moves towards democracy in the wake of three decades of Kadhafi's autocratic rule. - Sapa-AFP