WASHINGTON // The US no longer believes the attack on its consulate in Benghazi in which the US ambassador to Libya was killed was pre-planned, but continues to describe it as a "terrorist attack".
The US State Department is planning a new inquiry into the incident on September 11, which came after protests broke out across North Africa in response to a US-made movie that denigrates the Prophet Mohammed.
Hillary Clinton, the US secretary of state, James Clapper, the director of National Intelligence, and other state department, defence and intelligence officers briefed US legislators in private on Thursday about the attack.
The classified briefings included a look at US intelligence assessments before and during the attack amid criticism that the Benghazi consulate had not been sufficiently protected and that an attack, on the anniversary of the 2001 attacks in the US, might have been anticipated regardless of the furore over the Innocence of Muslims film.
Also included was an account of the events that led to the attack on the consulate, which left J Christopher Stevens, the US ambassador to Libya, and three other Americans dead.
The Federal Bureau of Investigation's attempt to identify suspects was also discussed but, according to US media accounts citing some of those present, no firm conclusions were presented about who or which groups were responsible.
The officials are understood to have briefed legislators that they do not believe that the attack was pre-planned, though some continue to resist that theory. Susan Collins, a Republican senator, had said during a similar but open briefing on Wednesday that she was "appalled" at the lack of security at the consulate.
"I just don't believe that people come to demonstrations equipped with RPG [rocket propelled grenades] and other heavy weapons," Ms Collins told a hearing of the Senate Homeland Security and Governmental Affairs committee.
She was responding to Matthew Olsen, director of the National Counterterrorism Centre.
Mr Olsen said that while intelligence agents believe militants in Benghazi and affiliates of Al Qaeda were involved in the attack, there had been no specific warnings and the "facts we have now, indicate this was an opportunistic attack".
"The picture that is emerging is one where a number of different individuals were involved, so it's not necessarily an either/or proposition," Mr Olsen said.
In a bid to pre-empt continued demonstrations, US consulates and embassies were closed yesterday in some Muslim countries, including Indonesia, the world's most populous Muslim country.
Raden Natalegawa, Indonesia's foreign minister, was in Washington on Thursday. He said the diplomatic missions had been closed after consultation with the US and as a precautionary measure, but also spoke to the broader issue of how to prevent future conflagrations over similar "incendiary" statements or films.
At the same press conference, Mrs Clinton said that the US had to remain engaged in Muslim countries where anti-US protests had erupted and especially in those emerging from the Arab Spring revolutions.
"There are obviously very real challenges in these new democracies, these fragile societies, but as I said last week, the vast majority of the people in these countries did not throw off the tyranny of a dictator to trade it for the tyranny of a mob."