LAST week's deadly assault on a US diplomatic mission in the Libyan city of Benghazi was a "terrorist attack" but probably not planned, a senior US official says.
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 against an anti-Islamic film.
In Washington, where President Barack Obama's election rival Mitt Romney has criticised the handling of the attack, there has been keen interest in whether the attackers were an angry mob or an organised gang.
On Wednesday, the director of the US government's National Counterterrorism Center told lawmakers that, while many questions remain, he was prepared to describe the killings as "a terrorist attack".
But the director, Matthew Olsen, immediately qualified that statement.
"The best information we have now, the facts that we have now indicate that this was an opportunistic attack on our embassy," he told the Senate homeland security committee.
"The attack began and evolved and escalated over several hours at our embassy, our diplomatic post in Benghazi. It evolved and escalated over several hours," he said, emphasising that a US investigation was continuing.
US Secretary of State Hillary Clinton was due to address a closed door secret intelligence briefing on Thursday, but in the meantime Olsen confirmed the Islamist militant group Al-Qaeda was among the suspects.
"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."
Initial reports into Tuesday's attack on the US consulate suggested it had been assaulted by protesters angered by an amateur movie produced in the US 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 planned attack.
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 against an anti-Islamic film.
In Washington, where President Barack Obama's election rival Mitt Romney has criticised the handling of the attack, there has been keen interest in whether the attackers were an angry mob or an organised gang.
On Wednesday, the director of the US government's National Counterterrorism Center told lawmakers that, while many questions remain, he was prepared to describe the killings as "a terrorist attack".
But the director, Matthew Olsen, immediately qualified that statement.
"The best information we have now, the facts that we have now indicate that this was an opportunistic attack on our embassy," he told the Senate homeland security committee.
"The attack began and evolved and escalated over several hours at our embassy, our diplomatic post in Benghazi. It evolved and escalated over several hours," he said, emphasising that a US investigation was continuing.
US Secretary of State Hillary Clinton was due to address a closed door secret intelligence briefing on Thursday, but in the meantime Olsen confirmed the Islamist militant group Al-Qaeda was among the suspects.
"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."
Initial reports into Tuesday's attack on the US consulate suggested it had been assaulted by protesters angered by an amateur movie produced in the US 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 planned attack.