Fresh protests erupted across the Muslim world on Friday against a US-made film and French cartoons mocking Islam, with violent demonstrations in Pakistan leaving at least 15 people dead.
In Middle Eastern and Asian countries tens of thousands took to the streets after the main weekly prayers to vent their anger, with little sign that the angry protests which began last week would abate.
Western missions were shut across the Islamic world, fearing further escalation of the backlash over the low-budget film "Innocence of Muslims" that has spread across the world.
France, where a magazine this week published a series of cartoons mocking the Prophet Mohammed, has shut embassies, consulates, cultural centres and schools in 20 Muslim countries, fearing the fury will spread from US targets.
Pakistan bore the brunt of the anger Friday, with huge crowds of demonstrators throwing stones and setting buildings ablaze to denounce the film.
There were clashes in the country's five largest cities leaving 15 dead and 219 others wounded, as protesters defied government calls for peaceful demonstrations on what was declared a national holiday in honour of Mohammed.
Witnesses estimated that nationwide rallies mobilised more than 45,000, mainly members of right-wing religious parties and supporters of banned terror groups, although the numbers were still small in a country of 180 million.
Police fought back with gunshots and tear gas as arsonists and looters attacked cinemas, banks, shops and restaurants in Karachi, where outbreaks of political and ethnically-linked violence have killed hundreds this year.
Two cinemas were also torched and ransacked in the northwestern city of Peshawar, on the edge of tribal belt strongholds of the Taliban and Al-Qaeda.
In Karachi, a policeman who died after being shot when officers used tear gas to disperse a crowd near the US consulate was among 10 people killed in the country's largest city.
Five people were killed in Peshawar, including the driver for a TV channel which blamed police for his death.
Police and paramilitary troops deployed en masse fired off volleys of tear gas to hold off protesters from breaching barricades that sealed access to Western embassies and consulates.
In Islamabad gunshots were also fired outside the five-star Serena Hotel and police baton-charged some 8,000 protesters trying to penetrate the heavily-guarded diplomatic enclave.
Protestors threw stones, shouting "Americans are dogs" and "Friends of America are traitors", while setting fire to an effigy of a nameless American.
The government had declared Friday a "day of love for the prophet", but for hours shut down mobile telephone networks in an apparent bid to prevent extremists from exploiting the protests to carry out bomb attacks.
"It is our collective responsibility to protest peacefully without causing harm or damage to life or property," said Prime Minister Raja Pervez Ashraf as shops, markets and petrol stations shut en masse in an unprecedented closure.
Washington has warned citizens not to travel to Pakistan and spent $70,000 to air TV adverts in the country disassociating the American government from the film, made by extremist Christians in the United States.
US Secretary of State Hillary Clinton on Friday reminded governments of their "solemn duty" to protect diplomatic missions, saying that "they must be safe and protected places".
While the protests turned ugly in Pakistan, in other Muslim countries there was no serious violence during demonstrations.
In the Arab world, Sunnis and Shiites took to the streets of Lebanon, while there were also demonstrations in Basra in south Iraq and in the Yemeni capital Sanaa.
Tunisia had banned all demonstrations amid fears of violence and Libya's second city Benghazi braced for rival demonstrations by a jihadist militia and its opponents.
Tensions are still running high after a deadly attack on the US consulate in the city last week which left Ambassador Chris Stevens and three other Americans dead.
The White House says the FBI suspects Al-Qaeda may have been linked to the attack, but it remains unclear whether it was a pre-planned assault or whether it sprang out of a protest against the film.
There were also demonstrations across Asia in Indonesia, Malaysia, Japan and Bangladesh, where about 10,000 took to the streets of Dhaka to condemn the film and the French cartoons.
US interests bore the brunt of protests against the film, which depicts Mohammed as a thuggish sexual deviant.
After French satirical weekly Charlie Hebdo printed cartoons caricaturing the founder of Islam, the government said it would deny requests to protest against the film and news of the cartoons appeared slow to filter to the Islamic world.
The magazine's editor, Stephane Charbonnier, mocked those angered by the cartoons as "ridiculous clowns" and accused the French government of pandering to them by criticising the magazine for being provocative.