WASHINGTON (AFP) - Last week's deadly assault on the US diplomatic mission in the Libyan city of Benghazi was a "terrorist attack" by militants who may have had Al-Qaeda ties, the White House said Thursday.
"It is self-evident that what happened in Benghazi was a terrorist attack," White House spokesman Jay Carney said, in a statement read to reporters on Air Force One.
"We are looking at indications that an individual involved in the attack may have had a connection to Al-Qaeda or Al-Qaeda affiliates," he added, citing Matthew Olsen, the director of the US National Counterterrorism Center.
"This is the best information what we have right now. There is an ongoing investigation," Carney said.
The attack, which left four Americans including US Ambassador Chris Stevens dead, was carried out on the 11th anniversary of the September 11 attacks and amid protests in the Muslim world against an anti-Islamic film.
Benghazi was the cradle of last year's Libyan revolt that ousted strongman Moamer Kadhafi, and the region is still prey to several loosely-organized militia groups with varying degrees of ties to the interim government.
Initial reports suggested the US consulate had been attacked by Islamist protesters angered by an amateur movie produced by private US Christian groups deemed insulting to the Prophet Mohammed.
But the gang that stormed the compound and torched the consulate was heavily-armed, and Libyan officials have said that a militant group took advantage of the protest to launch a pre-planned attack.
"The best information we have now, the facts that we have now indicate that this was an opportunistic attack on our embassy," Olsen told the Senate Homeland Security Committee on Wednesday.
"The attack began and evolved and escalated over several hours at our embassy -- our diplomatic post in Benghazi," he said, in Wednesday's briefing.
"At this point, what I would say is that a number of different elements appear to have been involved in the attack, including individuals connected to militant groups that are prevalent in eastern Libya," he said.
"We are looking at indications that individuals involved in the attack may have had connections to Al-Qaeda or Al-Qaeda's affiliates, in particular, Al-Qaeda in the Islamic Maghreb," the global network's North Africa franchise.
The nature of the assault has become a political issue in Washington, with Republican challenger Mitt Romney's presidential campaign pushing the idea that US President Barack Obama's administration was ill-prepared for it.