The obscure California-made film triggered an attack on the US consulate in Libya's city of Benghazi that killed the US ambassador and three other Americans on Tuesday, the anniversary of the September 11 2001 al-Qaeda attacks on the US.
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In Tunis, at least five people were wounded by police gunfire near the US embassy, and a Reuters reporter said a big fire had erupted within the embassy compound. Protesters had earlier leapt over the compound wall.
Witnesses said Sudanese police fired tear gas at thousands of protesters to stop them approaching the US embassy outside Khartoum, but some jumped over the wall. A Reuters reporter heard gunfire from the scene.
The wave of indignation and rage over the film, which portrays the Prophet Muhammad as a womaniser and a fool, coincided with Pope Benedict's arrival in Lebanon for a three-day visit.
The protests present US President Barack Obama with a new foreign policy crisis less than two months before seeking re-election and tests Washington's relations with democratic governments it helped to power across the Arab world.
It also emerged that Libya had closed its air space over Benghazi airport temporarily because of heavy anti-aircraft fire by Islamists aiming at US reconnaissance drones flying over the city, after Obama vowed to bring the ambassador's killers to justice.
The closure of the airport prompted speculation that the US was deploying special forces in preparation for an attack against the militants who were involved in the attack.
A Libyan official said the spy planes flew over the embassy compound and the city, taking photos and inspecting locations of radical militant groups who are believed to have planned and staged the attack on the US consulate.
There were protests in the Middle East, Africa and Asia.
Marines to Yemen
The Pentagon said it had sent a "fast" platoon of Marines to Yemen to bolster US embassy security after clashes in Sanaa.
US embassies were the main target of anger and protest but most embassy staff were not at work because Friday is the Muslim weekend across the Arab World.
The frenzy erupted after traditional Muslim Friday prayers. Fury over the film has been stoked by Internet video footage, social networks, preachers and word-of-mouth.
Protesters clashed with police near the US embassy in Cairo. Two Islamist preachers in Egypt told worshippers that those who made the movie deserved to die under sharia (Islamic law) but they urged protesters not to take their anger out on diplomats or others.
Sudanese demonstrators broke into the German embassy in Khartoum and hoisted an Islamic flag, while one person was killed in protests in the northern Lebanese city of Tripoli.
Police in the Sudanese capital had fired tear gas to try to disperse 5 000 protesters who had ringed the German embassy and nearby British mission. A Reuters witness said police stood by as a crowd forced its way into Germany's mission.
Demonstrators hoisted a black Islamic flag saying in white letters "there is no God but God and Mohammed is his Prophet". They smashed windows, cameras and furniture in the building and then started a fire.
Staff at Germany's embassy were safe "for the moment", Foreign Minister Guido Westerwelle said in Berlin. He also told Khartoum's envoy to Berlin that Sudan must protect diplomatic missions on its soil.
Sudan's Foreign Ministry had criticised Germany for allowing a protest last month by right-wing activists carrying caricatures of the Prophet and for Chancellor Angela Merkel giving an award in 2010 to a Danish cartoonist who depicted the Prophet in 2005 triggering protests across the Islamic world.
Bashir under pressure
President Omar Hassan al-Bashir is under pressure from Islamists who feel the government has given up the religious values of his 1989 Islamist coup.
The official body of Sudan's Islamic scholars called for the faithful to defend the Prophet peacefully, but at a meeting of Islamists, some leaders had said they would march on the German and US embassies and demanded the ambassadors be expelled.
The foreign ministry said in its statement: "The German chancellor unfortunately welcomed this offence to Islam in a clear violation of all meanings of religious co-existence and tolerance between religions."
Sudan used to host prominent militants in the 1990s, such as Osama bin Laden, but the government has sought to distance itself from radicals to improve ties with the West.
A Lebanese security source said a man was killed in Tripoli as protesters tried to storm a government building.
Earlier, a US fast food restaurant was set alight. Twelve members of the security forces were wounded by stones thrown by protesters, the source said.
Protesters also clashed with police in Yemen, where one person died and 15 were injured on Thursday when the US embassy compound was stormed.
US and other Western embassies in other Muslim countries had tightened security, fearing anger at the film may prompt attacks on their compounds after the weekly worship.
Obama has promised to bring those responsible for the Benghazi attack to justice, and the United States also sent warships towards Libya which one official said was to give flexibility for any future action.
US Secretary of State Hillary Clinton said Washington had nothing to do with the crudely made film posted on the Internet, which she called "disgusting and reprehensible", and the chairperson of the US Joint Chiefs of Staff called a Christian pastor in Florida to ask him to withdraw his support for it.
Palestinians staged demonstrations in both the occupied West Bank and Gaza Strip.
Israeli police, some on horseback, used stun grenades and made a number of arrests outside Jerusalem's Old City as a few dozen demonstrators tried to march on the nearby US consulate.
"Israeli police prevented an illegal demonstration from reaching the US consulate in East Jerusalem and used stun grenades after rocks and bottles were thrown at them," police spokesperson Micky Rosenfeld said.
In Nablus, in the northern West Bank, several hundred people protested and burned an American flag, witnesses said.
American flags burned
The largest protests were in the Gaza Strip, which is controlled by Islamist group Hamas, with at least 30 000 Palestinians staging rallies across the coastal territory.
Some 25 000 took to the streets of Gaza City, answering a call by Hamas and the smaller Islamic Jihad faction and waving the green and black flags of the two factions.
American and Israeli flags were set alight, along with an effigy of the film's producer.
Protesters in Afghanistan set fire to an effigy of Obama and burned a US flag after Friday prayers in the eastern province of Nangarhar.
Directing their anger against the US pastor who supported the film, tribal leaders also agreed to put a $100 000 bounty on his head.
About 10 000 people held a noisy protest in the Bangladeshi capital. They burned US flags, chanted anti-US slogans and demanded punishment for the offenders, but were stopped from marching to the US embassy. There was no violence.
Thousands of Iranians held nationwide protests. There were also rallies in Malaysia, Jordan, Kenya, Bahrain, Qatar, Bangladesh, Pakistan and Iraq. – Reuters