(MSNBC) -- Three people have been killed and 28 others have been injured in protests outside the U.S. Embassy in Tunis, Tunisia's official news agency said Friday as rage over an anti-Islamic video produced in California spread across much of the Muslim world.
At least two of the people killed in Tunis were protesters, the TAP news agency reported. The injured included both protesters and police.
Earlier, demonstrators set fire to the American School in Tunis, which was closed Friday.
The unrest has been mostly directed at U.S. embassies, but other targets also came under attack, including:
U.S. embassies and consulates had been braced for trouble on the Muslim day of prayer, when demonstrations are often held, following the attack on the consulate in Benghazi, Libya, which killed U.S. Ambassador Christopher Stevens and three other Americans.
Triggered by a crude, provocative anti-Islam video made by religious activists in the U.S. and uploaded to YouTube, angry protests by Muslims have been directed primarily at a number of U.S. diplomatic missions this week.
President Barack Obama has ordered a security review for U.S. diplomatic facilities worldwide, White House press secretary Jay Carney said Friday.
Obama, Vice President Joe Biden and Secretary of State Hillary Rodham Clinton were attending the return of the remains of the four Americans at Joint Base Andrews in suburban Maryland on Friday afternoon, the White House said.
Members of the Senate Armed Services Committee who were briefed by Defense Secretary Leon Panetta said Friday that it seemed clear that the Libya attacks were planned and premeditated. They cited the weapons carried by the attackers as the primary evidence.
"From all that I've heard," the attacks Tuesday night "were not just some coincidental protest of this film, this anti-Muslim film," said Sen. Joe Lieberman, I-Conn. "They were a well-planned and professional terrorist attack against the U.S. consulate in Benghazi."
Clashes in Cairo
In Egypt on Friday, stones were hurled at police near the U.S. Embassy in Cairo. "God is greatest" and "There is no god but God," one group chanted as police in riot gear fired tear gas and threw stones back at them in a street leading to the fortified U.S. Embassy.
Mohammed Morsi, an Islamist who is Egypt's first freely elected president, is having to strike a delicate balance, protecting the embassy of a major donor while also showing a robust response over the video.
NBC's Richard Engel in Egypt and NBC's Ayman Mohyeldin in Libya report on what might have triggered recent attacks on American facilities and U.S. history in the Middle East.
The Muslim Brotherhood said on Twitter that it was canceling its call for nationwide protests about the film. However, it said it would still be present in Cairo's central Tahrir Square "for a symbolic protest against the movie."
Cairo protesters have clashed with police daily since Tuesday, when angry young men scaled the walls of the U.S. Embassy and tore down and burned the U.S. flag, replacing it with a black Islamist one.
About 50 U.S. Marines have been sent to Yemen to provide additional security in the aftermath of Thursday's attack on the U.S. Embassy in Sanaa, Defense Department officials told NBC News. The Marines, part of a Fleet Anti-Terror Security Team, are an identical unit to the one sent to Libya earlier this week.
In Libya, a 48-hour no-fly zone was imposed over Benghazi in the wake of Tuesday's consulate attack, but it was later lifted.
Officials in Libya say they have arrested four suspects in connection to the deadly attack on the U.S. Consulate in Benghazi in which U.S. ambassador Stevens and three embassy staff were killed. NBC's Ayman Mohyeldin reports from Tripoli.
In Sudan, protesters clambered over the walls of the compound of the U.S. Embassy in Khartoum on Friday, prompting embassy guards to fire warning shots, a Reuters witness said.
Earlier, thousands of demonstrators trying to storm the British and German embassies clashed with police. Witnesses told Reuters that protesters got into the German Embassy, taking down the German flag and raising an Islamic one in its place.
The UN multi-national peacekeeping observer mission in the Sinai Peninsula was attacked Friday. Initial reports suggested that the watch tower was set on fire, but there were no reports of casualties. The multinational force observes the compliance of the Camp David peace treaty between Egypt and Israel.
In Lebanon, where Pope Benedict XVI arrived Friday for a three-day visit, hundreds of people set light to a KFC restaurant in the northern city of Tripoli, witnesses said. At least one person was killed and 25 others were wounded, Lebanese officials said.
In Indonesia, the world's most populous Muslim nation, about 200 protesters vented their anger by chanting "death to Jews!" and "death to America!" in a largely peaceful protest outside the heavily guarded U.S. Embassy in Jakarta.
In Pakistan, protests cropped up in major cities such as Lahore, Karachi and Islamabad, but Friday prayers seemed to have passed without major incidents of violence, NBC News reported.
About 200 demonstrators gathered Friday outside the U.S. Embassy in Kuwait and hoisted banners.
In Bangladesh, Islamists tried to march on the U.S. Embassy in Dhaka, and Iranian students protested in Tehran.
In Nigeria, where the radical Islamist sect Boko Haram has killed hundreds of people this year in an insurgency, the government put police on alert and stepped up security around foreign missions.
Protesters in Afghanistan set fire to an effigy of Obama and burned a U.S. flag after Friday prayers in the eastern province of Nangarhar.
Clinton said Thursday that Washington had nothing to do with the crudely made film posted on the Internet, which she called "disgusting and reprehensible."
The amateurish production, titled "Innocence of Muslims" and originating in the U.S., portrays Muhammad 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.
NBC's Richard Engel reports from Cairo, Egypt, where protesters, outraged over an anti-Islam video, continue to participate in violent demonstrations near the U.S. Embassy.
Ambassador Stevens was killed Tuesday during a protest against the film when Islamists armed with guns, mortars and grenades staged military-style assaults on the Benghazi mission.
Information technology specialist Sean Smith, an Air Force veteran, also died at the consulate, while two other Americans were killed when a squad of security personnel sent from Tripoli to rescue diplomats from a safe house came under mortar attack.
Clinton identified the two as Tyrone Woods and Glen Doherty, former Navy SEALS who died trying to protect their colleagues.