CAIRO — Anti-American violence erupted across the Muslim world for a third day, with enraged protesters scaling the walls of U.S. embassies in Sudan and Tunisia and hard-pressed police waging street battles with demonstrators in several Middle East capitals.
Protesters tore down the flag at the U.S. Embassy in Tunis, the Tunisian capital, and set a nearby American school afire. In Khartoum, Sudan's capital, demonstrators breached an embassy wall and raised a black flag of militant Islam as police struggled to push them back. They also set fire to a building at the German Embassy compound.
At least four protesters were reported killed — two in Tunisia, one in Yemen and one in the Lebanese city of Tripoli — during attacks on American fast-food franchises Hardee's and KFC. Armed Islamic militants attacked a multinational peacekeeping base in Egypt's Sinai peninsula, setting vehicles on fire and wounding at least three Colombian peacekeepers.
Triggered in large part by an amateurish video clip portraying the prophet Muhammad as a womanizer and child molester, the protests have strained U.S. relations with Egypt and raised tension in Libya, where an armed attack on the U.S. Consulate in Benghazi on Tuesday killed Ambassador J. Christopher Stevens and three other Americans.
The protests were a reminder of the passions unleashed by the "Arab Spring," which toppled authoritarian regimes across the region, the unfulfilled longings of millions for a better life and the weaknesses of new governments still trying to find their footing. New leaders such as Egyptian President Mohamed Morsi find themselves in a bind.
Morsi and the Muslim Brotherhood were caught flat-footed when their rivals in the ultraconservative Salafist movement called for protests outside the U.S. Embassy on Tuesday. The Brotherhood wants to maintain its legitimacy on the streets, but it also needs to court international support and investment. Morsi has been seeking forgiveness of $1 billion of his country's debt, as well as new international loans worth an estimated $4.8 billion.
"For the Muslim Brotherhood, there is always this sense of trying to protect their right flank and to not cede ground to the Salafists," said Michael Wahid Hanna, an expert on Egypt at the New York-based Century Foundation. "At some point in time, they have to make this jump from always playing the domestic angles and being careless with international issues."
The U.S. has responded with diplomatic pressure and by sending Marine guards to shore up security at U.S. missions in Libya and Yemen, where the U.S. embassy in Sana was stormed by demonstrators Thursday.
State Department officials said Friday that security services in some countries responded sluggishly and had to be pushed to step up protection of U.S. diplomats and property. But spokeswoman Victoria Nuland also softened the criticism, saying that in several cases post-authoritarian security forces weren't used to taking the initiative.
Secretary of State Hillary Rodham Clinton said that after U.S. prodding, the response in Tunisia was "very strong."
From Indonesia and Malaysia to Afghanistan and Pakistan, other demonstrators mounted less violent protests after Friday prayers. And in East Jerusalem, about 400 protesters trying to reach the U.S. Consulate threw stones and bottles at Israeli police, who held off the assault and arrested four people.
In Cairo, police had stood by Tuesday night as mobs stormed the U.S. Embassy, and Morsi failed for two days to publicly condemn the attack. At least 250 people were wounded during four days of skirmishes, according to Al Ahram newspaper.
After a sharply worded phone call from President Obama on Thursday, Morsi said during a televised address on Friday that it was a religious requirement "to protect our guests and their homes and places of work." He also condemned the killing of Stevens in Libya, saying it was unacceptable within Islam.
Outside the embassy in downtown Cairo on Friday, crowds were divided between peaceful protesters summoned by the Brotherhood, which has the largest faction in parliament, and a more violent group bent on confrontation.
"The U.S. ambassador must leave!" shouted a young man in the crowd. He was raised in the air, to cheers, by others as a group of several hundred protesters tried to storm past riot police.
The booms of police tear gas canisters rang out every few minutes. Injured demonstrators were lifted into ambulances as more protesters arrived to replace them.
Even as clouds of tear gas wafted across Tahrir Square, the rioting seemed as closely tied to Egypt's internal politics as to complaints about America. There was angry talk among the protesters that Morsi had not been tough enough.
In Tunis, government officials condemned the attack on the U.S. Embassy. President Moncef Marzouki called it "unjustifiable aggression" and said that those who caused it would be punished.
A mob of up to 5,000 people stormed the embassy earlier in the day, shouting, "We will have our revenge for our prophet!" as police fought to drive them back. A firebomb landed inside the compound and set part of a building on fire as two armed U.S. Marines took up positions on an embassy rooftop.
Police and military reinforcements, backed by three tanks, fired tear gas and rubber bullets. At least eight people in the crowd went down, and Tunisian state news later reported that two people had been killed and 29 wounded.
Demonstrators scaled a rear embassy wall, tore down an American flag and raised a black banner of militant Islam.
"American and European leaders didn't apologize for making fun of the prophet," said one protester, who identified himself as Rida, 22, a university student. "We will do anything to defend our faith."
In Yemen, security units surrounded the embassy in Sana, closing all routes nearby and dispersing several hundred demonstrators Friday. One person was killed, raising the death toll to five since Thursday.
Demonstrators on Friday carried banners that read, "This is your last day in Yemen, U.S. ambassador" and "The U.S. is the devil." But in Friday sermons, religious scholars in the capital condemned the violence, while also denouncing the U.S.-made video clip.
At Andrews Air Force Base near Washington, Obama attended a ceremony as the bodies of the Americans killed in Libya arrived on U.S. soil.
"The United States of America will never retreat from the world," Obama told friends and families of the men. "We will never stop working for the dignity and freedom that every person deserves, whatever their creed, whatever their faith.... That's the spirit that sets us apart from other nations."
At the ceremony, Clinton issued a veiled but steely warning to foreign leaders who fail to protect U.S. missions. "We've seen rage and violence directed at American embassies over an awful Internet video that we had nothing to do with," Clinton said. "It is hard for the American people to make sense of that, because it is senseless. And it is totally unacceptable.
"Reasonable people and responsible leaders in these countries need to do everything they can to restore security and hold accountable those behind these violent acts," she said, speaking slowly and emphatically.
The caskets arrived at the base shortly after 2 p.m. and were greeted by a Marine team that walked them to a hangar. Obama and Clinton stood in front of the caskets and briefly recalled the lives of the four men. When the ceremony concluded, the Marines placed the flag-draped caskets into their hearses, waiting to deliver them to Delaware's Dover Air Force base and to their families.