Libya's parliament chief announced in an interview with CBS News on Sunday the arrests of some 50 people over the killing of U.S. ambassador Chris Stevens in an attack he said was planned by foreigners.
U.S. Defence Secretary Leon Panetta said, meanwhile, the American military has no major plans to bolster its forces in the Middle East despite a week of violent protests targeting diplomatic outposts, including at the U.S. consulate in Libya's eastern city of Benghazi in which Mr. Stevens died.
"The number reached about 50," Mohammed al-Megaryef, president of the Libyan National Congress, told CBS News in an interview.
Mr. Stevens and and three other Americans were killed on Tuesday when suspected Islamic militants fired on the U.S. consulate in the eastern Libyan city with rocket-propelled grenades and set it ablaze.
Mr. Megaryef said "a few" of those who joined in the attack were foreigners, who had entered Libya "from different directions, some of them definitely from Mali and Algeria."
"The others are affiliates and maybe sympathizers," he added.
Mr. Megaryef said the government has learned the attack was not the result of a spontaneous outburst of anger over Innocence of Muslims, a U.S.-made anti-Islamic movie which has triggered sometimes deadly protests in the Arab and Muslim world.
"It was planned, definitely, it was planned by foreigners, by people who entered the country a few months ago. And they were planning this criminal act since their arrival," he told CBS.
However, the U.S. ambassador to the United Nations says the attack on the U.S. consulate in Benghazi, Libya, was spontaneous.
Susan Rice told Fox News Sunday that protesters gathering near the consulate were joined by others with extremist ties. She says they brought heavy weapons possibly left over from the Libyan revolution last year.
The current U.S. assessment shows it was not a co-ordinated, premeditated attack, Ms. Rice said.
Al-Qaeda in the Arabian Peninsula has said in a statement the attack was in revenge for the killing of the terror network's deputy leader Sheikh Abu Yahya al-Libi in a drone strike in June.
In cities across the Muslim world protesters have since vented their fury at the film by targeting symbols of U.S. influence ranging from embassies and schools to fast food chains.
Although the U.S. government itself has condemned the film, protests erupted again on Sunday, with hundreds of students pouring into the streets of Kabul shouting anti-American slogans, as the Bangladesh government condemned the film as "reprehensible" and New Delhi said it was "offensive."
Hundreds of Pakistanis protesting an anti-Islam video produced in the United States clashed with police as they tried to march toward the U.S. Consulate in the southern city of Karachi. Thousands of other people held peaceful protests against the film in several other cities in Pakistan.
Belgian police said they detained 230 people in the northern city of Antwerp after clashes at a demonstration against an the film.
With Muslim anger boiling, Al-Qaeda in the Arabian Peninsula on Saturday issued a call for more violence against U.S. diplomatic missions in the Middle East and Africa, and urged attacks on American interests in the West, the SITE Intelligence Group said.
A filmmaker linked to the anti-Islamic movie said following an interview with law enforcement officials that would not return to his home, possibly heading into hiding, authorities said.
Nakoula Basseley Nakoula, 55, was interviewed by federal probation officers for about half an hour at the station shortly after 12 a.m. Sunday in his hometown of Cerritos, California, said Steve Whitmore, spokesman for the Los Angeles County sheriff's department.
After that, deputies dropped Mr. Nakoula off at an undisclosed location.
"He is gone. We don't know where he went," Mr. Whitmore said. "He said he is not going back to his home."
Federal officials are investigating whether Nakoula, who has been convicted of financial crimes, has violated the terms of his five-year probation. If so, a judge could send him back to prison.
Mr. Nakoula went voluntarily to the station, wearing a coat, hat, scarf and glasses that concealed his appearance. His home has been besieged by media for several days.
Mr. Whitmore said Mr. Nakoula was not handcuffed and the heavy apparel was his idea.
The probation department is reviewing the case of Mr. Nakoula, who pleaded no contest to bank fraud charges in 2010 and was banned from using computers or the Internet or using false identities as part of his sentence. Mr. Whitmore did not disclose other details about the interview.
Federal authorities have identified Mr. Nakoula, a self-described Coptic Christian, as the key figure behind Innocence of Muslims.
Much of the film was shot inside the offices of Media for Christ, a non-profit based in the Los Angeles-area city of Duarte. The charity raised more than $1-million (U.S.) last year "to glow Jesus' light" to the world.
With a report from The Associated Press