SANAA, Yemen — Deadly outrage in the Arab world over a U.S.-made video insulting Islam's founder spread to at least half a dozen places across the Middle East on Thursday and threatened to draw in Afghanistan, two days after assailants in Libya killed four U.S. diplomatic personnel and caused a foreign policy crisis in Washington.
The worst of the violence was in Yemen, where at least five Yemenis were killed as hundreds of protesters stormed the U.S. Embassy and were repulsed by Yemeni security forces.
The embassy's entire staff, sensitive to impending danger, had been safely evacuated hours beforehand. Yemeni leaders apologized to President Obama for the mayhem.
But some assailants were able to burn cars, plunder office equipment, burn an American flag, and hoist their own proclaiming fealty to Islam. Witnesses and Yemeni officials said at least 10 U.S. Embassy vehicles had been damaged or destroyed by fire.
By nightfall, witnesses said, smoke was still rising from the embassy compound in the eastern part of the capital, Sanaa, as protesters still raged from a perimeter 400 yards away.
In Egypt, where the anti-American anger began Tuesday over the video, protesters scuffled with police officers firing tear gas. News agencies reported that dozens of people were hurt.
Demonstrations were also reported outside U.S. diplomatic facilities in Morocco, Sudan, and Tunisia — where the police fired tear gas to disperse the crowds — and an anti-American protest was held in the Palestinian enclave of Gaza.
In Iran, where nearly all large protests must get government approval, witnesses and news reports said 500 Iranians screaming "Death to America!" converged outside the Swiss Embassy, which handles U.S. diplomatic interests, and were restrained by police.
Authorities in Afghanistan, where deadly violence has flared in the past over perceived insults to Islam, scrambled to minimize the possibility that the offending video, which portrays the Prophet Mohammed as a perverted buffoon, could be viewed on the Internet and provoke new protests.
Afghanistan officials said they had pressed for an indefinite suspension of access to YouTube, where the video, promoted by right-wing Christians in the United States, had received more than 1.6 million hits by Thursday afternoon.
Little is known about the origin of the video that provoked the protests, which is called "Innocence of Muslims."
It was made in obscurity somewhere in Southern California and promoted by a network of right-wing Christians with a history of animosity toward Muslims. When a 14-minute trailer of it was posted on YouTube in June, it was barely noticed.
In Washington, Secretary of State Hillary Clinton delivered a denunciation of the video in what her spokesman later said was an effort to quash the mistaken belief in some parts of the Arab world that the U.S. government somehow had sponsored or condoned it.
"To us, to me personally, this video is disgusting and reprehensible," Mrs. Clinton said at a briefing with Morocco's foreign minister at the State Department. "It appears to have a deeply cynical purpose: to denigrate a great religion and to provoke rage."
She went on to say the Constitution did not allow the United States to "prevent these kinds of reprehensible videos from ever seeing the light of day," and could not if it tried, given modern technology.
The production portrays Mohammed as a womanizer, a homosexual, and a child abuser.
For many Muslims, any depiction of the prophet is blasphemous and caricatures or other characterizations have in the past provoked violent protests across the Muslim world.
Federal authorities have identified a Southern California man who is on federal probation for financial crimes as the key figure behind the film, a U.S. law enforcement official told the Associated Press on Thursday.
There was no sign of Nakoula Basseley Nakoula, 55, at his family's home Thursday in Cerritos outside Los Angeles.
Attorney General Eric Holder confirmed that the Justice Department has opened a criminal investigation into the deaths of the U.S. ambassador to Libya and three other diplomats killed during an attack on the American mission in Benghazi.
It was not clear whether authorities were focusing on Nakoula as part of that probe.
Much about the film remains a mystery, including who financed it.
Several actors have come forward and claimed they were duped about their roles, and that incendiary language was dubbed over their lines.
Questions remained about whether Nakoula's filmmaking and Internet distribution activities might have violated his federal probation and send him back to prison.
Nakoula pleaded no contest in 2010 to federal bank fraud charges in California and was ordered to pay more than $790,000 in restitution. He was sentenced to 21 months in federal prison and ordered not to use computers, the Internet, or online user or screen names for five years without approval from his probation officer.
He is still on probation, according to court records.
The new violence occurred as news reports from Libya said the authorities there had made at least four arrests in connection with the killings of the four Americans in the mayhem that engulfed the U.S. Consulate in the eastern city of Benghazi on Tuesday night.
The Yemen protests occurred hours after a Muslim cleric, Abdul Majid al-Zindani, urged followers to emulate the protests in Libya and Egypt, Sanaa residents said.
Al-Zindani, a onetime mentor to Osama bin Laden, was named a "specially designated global terrorist" by the U.S. Treasury Department in 2004.
The crowd gathered a day after the embassy warned Americans in a posting on its Web site, "In the wake of recent events in Libya and Egypt, there is the possibility of protests in Yemen, and specifically near the U.S. Embassy, in the coming days.
"The U.S. Embassy continues to recommend that U.S. citizens avoid large gatherings. Even demonstrations or events intended to be peaceful can turn confrontational and possibly escalate into violence. U.S. citizens in Yemen are urged to monitor local news reports and to plan their activities accordingly," the Web posting said.
President Abed Rabbo Mansour al-Hadi of Yemen said he extended his "sincere apologies to President Obama and to the people of the United States of America" for the attack.
Mr. al-Hadi took office in February after his strongman predecessor, Ali Abdullah Saleh, stepped down in November after months of violent protests.
With U.S. Marines and naval vessels heading for Libya, the ferment in Yemen and elsewhere added to the volatile mix of passions that have commingled with the initial exuberance of the so-called Arab Spring.
In an effort to defuse the tension in Egypt, President Mohammed Morsi said Thursday the attacks on U.S. personnel were unacceptable.
Speaking in a television address while visiting Brussels, Mr. Morsi said he supported peaceful demonstrations but rejected attacks on personnel and diplomatic missions.15.35203 44.20745
Protests against U.S.-made film insulting Islam spreads across Middle East.