The United States suspects a deadly attack on a US consulate in Libya was a well-planned assault by militants instead of a rampaging mob, US officials said Wednesday, renewing concerns about the role of extremists in the wake of the Arab Spring.
The attackers appear to have used protests over an inflammatory film as a pretext to stage a major assault involving small arms fire and rocket-propelled grenades that lasted several hours, overwhelming the security team at the consulate in Benghazi.
"That's the working hypothesis at the moment," said a senior US official, who spoke on condition of anonymity.
"This was a complex attack," he told AFP. "They seemed to have used this (protest) as an opportunity."
The gunmen, who opened fire on the American consulate and kept US security teams at bay for hours, may have had links to Al-Qaeda or been inspired by the terror network, officials said, stressing that investigators needed more time to gather facts.
"It is too early to definitively attribute the attack to Al-Qaeda or its affiliates," the official said.
However, the chairman of the House Intelligence Committee, Mike Rogers, said the attack that killed the US ambassador, Chris Stevens, and three of his staff resembled an Al-Qaeda operation.
"There are still some fuzzy details... but clearly it has all the hallmarks of an Al-Qaeda-style event," the Republican lawmaker told CNN.
Tuesday's assault came amid a wave of protests in Muslim countries against a US-made amateur Internet film that mocks the Prophet Mohammed.
Initial accounts suggested the assault was the result of violent riots but as more details emerged, officials and experts said the evidence pointed to a deliberate plot staged to mark the anniversary of the September 11, 2001 attacks on the United States.
In response to Tuesday's attack, the United States dispatched two naval destroyers to waters off Libya and deployed a 50-strong counter-terrorism team of US Marines to bolster security at its Tripoli embassy.
The United States also has unmanned drone aircraft at its disposal to help Tripoli track militants who may have carried out the attack, officials said.
The surveillance drones have been flying over Libya since the NATO-led air war that helped topple Moamer Kadhafi last year, officials said, adding that Washington enjoys friendly relations with Tripoli and shares intelligence with the new leadership.
"We have those capabilities in the region and have had them for some time," one defense official said.
US officials portrayed the movement of warships as a "precautionary" step but the decision also reflected worries about instability in Libya and elsewhere in the wake of popular Arab uprisings.
The United States has publicly backed calls for democratic reforms in the Middle East but officials have privately worried that staunch Arab allies could be endangered and that Islamist militants are taking advantage of the uprisings, with Al-Qaeda loyalists gaining new footholds.
The violence at the consulate marked the first time a US ambassador was killed in the line of duty since the 1970s, raising questions about security at the Benghazi outpost, including how the attackers were able to breach the compound within 15 minutes after opening fire.
Senior officials described to reporters a harrowing siege of the consulate that began with gunfire at about 10:00 pm and lasted for more than three hours until Libyan forces moved in to restore order.
Security appeared to have collapsed, with an office building engulfed in flames as guards searched in vain for Ambassador Chris Stevens amid a barrage of bullets, officials said.
It took two attempts before the Americans were able regain control of the consulate's main building, and then Libyan forces were needed to push back the attackers from a separate annex.
A picture taken by an AFP photographer shows what witnesses say is an injured Stevens being helped by Libyans inside the compound. He later was reportedly taken to a Benghazi hospital by Libyans, but US officials say they did not see him until his corpse was transported to the local airport.
US officials in Libya had conducted a security review in the run-up to the 9/11 anniversary but had seen no intelligence reporting that hinted to a heightened threat, the officials said.
The consulate, which includes a number of buildings, had "robust" security, including local forces posted outside, a perimeter of physical barriers and a security team employed by the State Department, officials said.
A unit of US Marines guards the US embassy in Tripoli. But the consulate in Benghazi, unlike some American diplomatic outposts, had no team of Marines on the ground.