Was Ambassador Christopher Stevens on an Al Qaeda hit list?

US Ambassador to Libya Christopher Stevens, who was killed last week in an attack on the US consulate in Benghazi, believed he was on an "Al Qaeda hit list," according to a report by CNN.

The network has spoken to an anonymous source "familiar with [Stevens's] thinking," who says that, months before he died, the ambassador expressed concern about "never-ending security threats" and the growing presence of Islamic extremists, including Al Qaeda.

Stevens even said his name was on the terrorists' "hit list," according to the source. CNN's report doesn't say where Stevens got his information.

A top US counterterrorism official has suggested that the attack on the US consulate in Benghazi may have been carried out by people with links to Al Qaeda.

Speaking at a Senate hearing yesterday, National Counterterrorism Center Director Matthew Olsen described the violence as a "terrorist attack." However, he also said that it appeared to have been "opportunistic."

 "We do know that a number of militants in [the] area […] are well armed and maintain those arms," Olsen told the hearing, according to CNN. "What we don't have at this point is specific intelligence that there was a significant advanced planning or coordination for this attack."

More from GlobalPost: Libya attack was terrorism, but not planned in advance, says counterrorism official

That account differs from Libya's version of events. Libya's president, Mohamed Magariaf, told CBS that the attack "was planned by foreigners, by people who entered the country a few months ago, and they were planning this criminal act since their arrival."

Few people would dispute that Benghazi was a dangerous place to be during Stevens's final months. The US consulate had already been attacked with a bomb in June, while British embassy vehicles were also targeted.

Some lawmakers are asking why, then, diplomats like Stevens and his three colleagues who died weren't better protected. Sen. Susan Collins (R-Maine), quoted by the Associated Press, told yesterday's hearing she was "stunned and appalled that there wasn't better security for all of the American personnel at that consulate, given the high-threat environment."

Questioned on the matter earlier this week, US Secretary of State Hillary Clinton said that authorities had had "no actionable intelligence that an attack on our post in Benghazi was planned or imminent."

"Our diplomats engage in dangerous work," Clinton said, "and it's the nature of diplomacy in fragile societies and conflict zones to be aware of the necessity for security but to also continue the important diplomatic work that has to go on."