WASHINGTON - In the months leading up to his death, Chris Stevens, the U.S. ambassador to Libya, worried about constant security threats in Benghazi and mentioned that his name was on an al Qaeda hit list, a source familiar with his thinking told CNN.
Stevens spoke about a rise in Islamic extremism and al Qaeda's growing presence in Libya, the source said.
Matthew Olsen, director of the U.S. National Counterterrorism Center, said it is unlikely that Stevens and his security team were killed by random protesters.
"I would say yes, they were killed in the course of a terrorist attack on our embassy," Olsen said Wednesday at a Senate Homeland Security Committee hearing.
Stevens and three other Americans were killed September 11 during a large protest at the U.S. Consulate in Benghazi. Demonstrators were angry about a film made in the United States that mocked the Muslim Prophet Mohammed.
Sources tracking militant Islamist groups in the region said that a pro-al Qaeda group was the chief suspect and that the attack appeared to have been planned. The attackers used the protest as a diversion, the sources said.
Libyan and U.S. officials are attending a memorial service Thursday in Tripoli for the four Americans.
Washington tried to distance itself from the uproar, making it clear that it did not sanction the film. But more than a week of protests have rippled from Morocco to Malaysia, spurring U.S. officials to increase security at diplomatic missions and demand other governments to take action.
Here are some of the latest key developments in the fallout from the anti-Islam film and from cartoons published in a French satirical magazine featuring a figure resembling Mohammed:
Anti-U.S. protests in Afghanistan, Pakistan
Hundreds of protesters took part in a rally in Kabul, Afghanistan.
They chanted, "Long live Islam, death to America," and "Mohammed is our messenger."
In Islamabad, Pakistan, protesters demonstrated outside the diplomatic enclave that houses foreign embassies, including the U.S. and French embassies.
As many as 1,500 took part, slamming the anti-Islamic movie and the subsequent publishing of satirical cartoons depicting the Mohammed in a French magazine.
Police used tear gas and fired warning shots into the air to disperse the crowd.
Islamabad Police Chief Bin Yamin said some protesters clashed with police, leaving eight police injured.
It was not immediately clear how many protesters were injured.
The demonstration began with a small group of protesters, who were joined by a larger rally organized by Sipah-e-Sahaba, a banned hard-line Sunni Islamist group that's fiercely anti-Shia, Yamin said.
The protest later dispersed, he said.
Also Thursday, Iranian demonstrators gathered in Tehran's Palestinian Square to protest the anti-Islamic film, shouting slogans against the United States and Israel and "those who insulted the holy prophet," said the state-run Iranian news agency IRNA.
Anti-France protests in Iran
Iranian students also demonstrated in front of the French Embassy in Tehran on Thursday, the semiofficial FARS news agency reported.
The protest came a day after the French satirical magazine Charlie Hebdo added to the fiery debate between freedom of expression and offensive provocation.
The magazine known for outrageous humor published cartoons featuring a figure resembling Mohammed.
So far, there has been no violence reported as a result of the Charlie Hebdo cartoons.
Still, France will close embassies and schools in about 20 countries Friday, the main Muslim day of prayer, as a precaution, the French Foreign Ministry said.
It is already boosting security in some locations, including its embassies, and police vehicles were parked outside the Paris offices of Charlie Hebdo earlier this week.
In the past, Muslims in many countries have taken to the streets after Friday prayers.
Any depiction of Islam's prophet is considered blasphemy by many Muslims. France has the largest Muslim population in Western Europe, with an estimated 4.7 million followers of the faith.
The Charlie Hebdo cartoons are not labeled Mohammed, but several, including one that appears to show a man's naked rear end, could easily be interpreted as being depictions of Islam's prophet.
On Thursday, the Paris prosecutor's office said a group called the Syrian Association of Freedom filed a complaint against the magazine for inciting hatred. The magazine turned to the prosecutor's office, asking for an inquiry after its website was hacked.
German magazine may add to debate
Meanwhile, the German satirical magazine Titanic will publish an issue lampooning Islamophobia next week, with a depiction on its cover that could be interpreted as being Mohammed.
Staffer Martina Werner said the Titanic issue will take on film and politicians making political capital on Islamophobia with a cover from an old movie poster.
Asked if it is supposed to depict Mohammed, Werner answered: "Well, that lies in the eye of the beholder."
Capitol Hill briefings