* Violent protests erupt in Pakistani cities
* Demonstrations stay peaceful elsewhere in Muslim world
* France bans street protests over cartoons
By Aisha Chowdhry
ISLAMABAD, Sept 21 (Reuters) - Muslim protests against insults to the Prophet Mohammad turned violent in Pakistan, where six people were killed on Friday, the Muslim day of prayer, but remained mostly peaceful in Islamic countries elsewhere.
In France, where the publication of cartoons denigrating the Prophet stoked anger over an anti-Islam video made in California, the authorities banned all protests over the issue.
"There will be strictly no exceptions. Demonstrations will be banned and broken up," said Interior Minister Manuel Valls.
Tunisia's Islamist-led government also banned protests against the images published by French satirical weekly Charlie Hebdo. Four people were killed and almost 30 wounded last week when the U.S. embassy was stormed in a protest over the film.
Many Western and Muslim politicians and clerics have appealed for calm, denouncing those behind the mockery of the Prophet, but also condemning violent reactions to it.
At street level, Muslims enraged by attacks on their faith spoke of a culture war with those in the West who put rights to freedom of expression above any religious offence caused.
"They hate him (the Prophet Mohammad) and show this through their continued works in the West, through their writings, cartoons, films and the way they launch war against him in schools," said Abdessalam Abdullah, a preacher at a mosque in Beirut's Palestinian refugee camp of Bourj al-Barajneh.
Muslims generally consider any depiction of the Prophet blasphemous.
Western diplomatic missions in Muslim nations tightened security ahead of Friday prayers. France ordered its embassies, schools and cultural centres to shut in a score of countries.
In Pakistan, tens of thousands of people joined protests encouraged by the government in several cities including Islamabad, Karachi, Peshawar, Lahore, Multan and Muzaffarabad.
The bloodiest unrest erupted in the southern city of Karachi, where three policemen and two protesters were killed and 112 people wounded, according to Allah Bachayo Memon, spokesman of the chief minister of Sindh province. He said about 20 vehicles, three banks and five cinemas were set on fire.
Crowds set two cinemas ablaze and ransacked shops in the northwestern city of Peshawar, clashing with riot police who fired tear gas. At least five protesters were hurt and the ARY television station said an employee had been killed.
Mohammed Tariq Khan, a protester in Islamabad, said: "Our demand is that whoever has blasphemed against our holy Prophet should be handed over to us so we can cut him up into tiny pieces in front of the entire nation."
Security forces fired in the air in Peshawar and the eastern city of Lahore to keep protesters away from U.S. consulates. Police fired tear gas at about 1,000 protesters in Islamabad.
The U.S. embassy in Pakistan has run television spots, one featuring Secretary of State Hillary Clinton, saying the government had nothing to do with the film about Mohammad.
Pakistan declared Friday a "Day of Love" for the Prophet and Prime Minister Raja Pervez Ashraf said an attack on Islam's founder was "an attack on the whole 1.5 billion Muslims".
The foreign ministry summoned the U.S. chargé d'affaires to lodge a protest over the video posted on YouTube, the latest in an array of irritants poisoning U.S.-Pakistani relations.
In neighbouring Afghanistan, police contacted religious and community leaders to try to prevent bloodshed. Protests in Kabul and the northern city of Mazar-e-Sharif only attracted a few hundred people and no violence was reported, but a cleric told one crowd: "If you kill Americans, it's legal and allowable."
About 10,000 Islamists gathered in the Bangladeshi capital, Dhaka, after Friday prayers, chanting slogans and burning U.S. and French flags and an effigy of U.S. President Barack Obama.
Protests went off peacefully in the Arab world, where last week several embassies were attacked and the U.S. envoy to Libya was killed in an initial burst of unrest over the film.
In Yemen, where the U.S. embassy was stormed last week, several hundred Shi'ite protesters chanted anti-American slogans, but riot police blocked the route to the embassy.
Anger over the film brought several thousand Shi'ites and Sunnis together in a rare show of sectarian unity in Iraq's southern city of Basra, where they burnt U.S. and Israeli flags.
Lebanon's Hezbollah-run al-Manar television showed thousands of people waving Lebanese and yellow Hezbollah flags as they marched past the Roman ruins of Baalbek and shouted slogans such as "Death to America, death to those who insult the Prophet".
A Beirut protester, who gave his name as Ahmed, called for a boycott of Western products. "They hate us and want to get rid of our culture and we will resist. We should reject all aspects of their culture too," the 23-year-old student said, wearing jeans and an orange t-shirt with English writing on it.
The violence provoked by the film has led to a total of about 30 deaths so far, a United Nations official said.
"Both the film and the cartoons are malicious and deliberately provocative. The film particularly portrays a disgracefully distorted image of Muslims," Rupert Colville, spokesman for U.N. High Commissioner for Human Rights Navi Pillay, told a news briefing in Geneva.
He said Pillay upheld people's right to protest peacefully, but saw no justification for violent and destructive reactions.
"In the case of Charlie Hebdo, given that they knew perfectly what happened in response to the film last week, it seems doubly irresponsible on their part to have published these cartoons," Colville said of the French magazine.