Consulate attack in Libya entailed "coordinated assault" involving 100, sources say About 100 attackers carried out a "coordinated assault" last week on the U.S. Consulate in Benghazi, Libya, intelligence sources tell Fox News, further discrediting earlier Obama administration claims that the deadly attack was a "spontaneous" outburst in response to an anti-Islam film. Fox News' sources say the attack came in two waves and involved rocket-propelled grenades, as well as mortar fire, and both the consulate and safe house were attacked seemingly with inside knowledge. Libyan officials are now "absolutely convinced" the attack was preplanned, sources say, adding to recent indications that Al Qaeda was involved, specifically a former Guantanamo detainee named Sufyan Ben Qumu. Four Americans, including U.S. Ambassador Chris Stevens, were killed in the strike, which occurred on the 11th anniversary of the Sept. White House Press Secretary Jay Carney and Susan Rice, the U.S. ambassador to the United Nations, initially described the attack on the consulate as spontaneous with little evidence of a well-planned assault. Administration officials also pointed to the anti-Islam film that has fueled protests in the Mideast against the United States, suggesting the consulate attack may have begun as one of those protests and escalated. But this week, the administration began shifting its explanations for the attack, with National Counterterrorism Center Director Matt Olsen testifying before the Senate on Wednesday that it was a "terrorist attack." Carney followed up by saying for the first time Thursday that it was "self evident" that the attack was an act of terrorism, but President Obama seemed to backtrack a bit when pressed later that day by a TV interviewer. Obama did not reference terrorism, instead invoking the controversial film, which some analysts have said is being used as a tool of extremists to incite violence. Qumu, the former Guantanamo Bay detainee, is a Libyan who was released from the U.S. prison in Cuba in 2007 and transferred into Libyan custody on the condition he be kept in jail. Fox News' Bret Baier and Catherine Herridge contributed to this report.