(Adds government reaction)
By Emma Thomasson and Alexandra Hudson
AMSTERDAM, March 27 (Reuters) - Dutch lawmaker Geert Wilders launched a film on Thursday that accuses the Koran of inciting violence and warns that Muslim immigrants threaten the West, prompting the government to appeal for calm.
The film "Fitna" was posted on his Freedom Party's Web site (www.pvv.nl), which crashed soon afterwards. But it could still be viewed on a file-sharing Web site in English and Dutch.
Dutch broadcasters had refused to show the film and a U.S.-based web service which Wilders had planned to use deactivated the site at the weekend after receiving complaints.
The Dutch government is anxious to avert the kind of Muslim backlash Denmark suffered in 2006 over cartoons of the Prophet Mohammad. Prime Minister Jan Peter Balkenende said on Thursday he rejected the film's attempt to link Islam with violence.
Wilders has been under heavy guard because of Islamist death threats since the 2004 murder of Dutch director Theo van Gogh, who made a film critical of Islam's treatment of women.
"Fitna", a Koranic term sometimes translated as "strife", intersperses shots of the Sept. 11, 2001 attacks and other bombings with quotations from the Koran.
"Prepare for them whatever force and cavalry ye are able of gathering to strike terror, to strike terror in the hearts of the enemies of Allah and your enemies," the first quote reads.
The film warns that the rising number of Muslims in the Netherlands and the rest of Europe threatens democratic values.
After the caption "The Netherlands in the future?" the film shows images of gay men being executed, children with bloody faces, a woman being stoned and another of genital mutilation.
It shows an image of the Koran followed by the sound of ripping paper: "The sound just heard was a page being torn from a phone book, as it is not for me but for Muslims themselves to tear out the hate-filled verses from the Koran," a caption says.
After the words "Stop Islamisation. Defend our freedom", the film concludes with a cartoon of the Prophet Mohammad with a bomb under his turban that was originally published in Danish newspapers, accompanied by the sound of ticking.
"We believe it serves no purpose other than to cause offence," Balkenende told a news conference. "But feeling offended should never be used as an excuse for aggression and threats."
He added he was heartened by the initial restraint of Dutch Muslims.
Brahim Bourzik, a spokesman for a Dutch Moroccan group, said mosques would open their doors on Friday to help defuse tension.
"It is not a film -- it is propaganda. All the elements have been seen before, there is nothing new in it," he said, adding he hoped there would not be an angry reaction at home or abroad.
Demonstrators have already taken to the streets from Afghanistan to Indonesia to burn Dutch and Danish flags, while the governments of Pakistan and Iran have sharply criticised the film. About a thousand people protested against Wilders in Amsterdam on Saturday.
NATO had expressed concern the film could worsen security for foreign forces in Afg`anistan, including 1,650 Dutch troops.
Earlier this month, Dutch security officials raised the national risk level to "substantial" because of the Wilders film and perceptions of an increased al Qaeda threat.
Van Gogh's killing by an Islamist militant triggered a wave of unrest in the Netherlands, home to almost 1 million Muslims out of a total population of 16 million.
Wilders, a right-winger, said he hoped the film would not put Dutch people at risk: "If something should happen, which I hope won't be the case, then the people who use threats or violence, they are responsible."
Dutch exporters have expressed fears of a possible boycott in the Muslim world, though trade with such countries makes up only a small amount of total exports. There is also concern for 25,000 Dutch citizens living in Muslim countries. (Additional reporting by Niclas Mika, Foo Yun Chee and Gilbert Kreijger; editing by Andrew Roche)