(Adds reaction by Belgium, Islamists)
By Niclas Mika
AMSTERDAM, March 28 (Reuters) - Muslim nations on Friday condemned a film by a Dutch lawmaker that accuses the Koran of inciting violence, and Dutch Muslim leaders urged restraint.
Geert Wilders, leader of the anti-immigration Freedom Party, launched his short video on the Internet on Thursday evening, prompting an al Qaeda-linked website to call for his death and increased attacks on Dutch soldiers in Afghanistan.
"The correct Sharia (Islamic law) response is to cut (off) his head and let him follow his predecessor, van Gogh, to hell," a member of Al-Ekhlaas wrote on the al-Qaeda affiliated forum, according to the SITE Institute, a U.S.-based terrorism monitoring service.
Dutch director Theo van Gogh, who made a film accusing Islam of condoning violence against women, was murdered by a militant Islamist in 2004.
Wilders’ film "Fitna" -- an Arabic term sometimes translated as "strife" -- intersperses images of the Sept. 11, 2001 attacks on the United States and Islamist bombings with quotations from the Koran, Islam’s holy book.
The film urges Muslims to tear out "hate-filled" verses from the Koran and starts and ends with a cartoon of the Prophet Mohammad with a bomb under his turban, accompanied by the sound of ticking.
The cartoon, first published in Danish newspapers, ignited violent protests around the world and a boycott of Danish products in 2006. Many Muslims regard any depiction of the Prophet as offensive.
"The film is solely intended to incite and provoke unrest and intolerance among people of different religious beliefs and to jeopardise world peace and stability," the 57-nation Organisation of the Islamic Conference (OIC) said.
U.N. Secretary-General Ban Ki-moon condemned the film as "offensively anti-Islamic" and U.N. High Commissioner for Human Rights Louise Arbour said it was "hateful".
Iran called the film heinous, blasphemous and anti-Islamic, and Indonesia, the world’s most populous Muslim nation and a former Dutch colony, said it was an "insult to Islam, hidden under the cover of freedom of expression".
The Saudi Arabian embassy in The Hague said the film was provocative and full of errors and incorrect allegations that could lead to hate towards Muslims, news agency ANP reported.
Dutch Muslim leaders appealed for calm and called on Muslims worldwide not to target Dutch interests. The Netherlands is home to about 1 million Muslims out of a population of 16 million.
"Our call to Muslims abroad is follow our strategy and don’t frustrate it with any violent incidents," Mohammed Rabbae, a Dutch Moroccan community leader, told journalists in an Amsterdam mosque.
The Dutch Islamic Federation went to court on Friday to try to stop Wilders from comparing Islam to fascism.
Pollster Maurice de Hond found that only 12 percent of those questioned thought the film represented Islam accurately, but 43 percent agreed Islam was a serious threat to the Netherlands over the long term.
Wilders has been under guard because of death threats since the murder of van Gogh and Freedom Party support rose in anticipation of the film to about 10 percent of the vote.
The Dutch government has distanced itself from Wilders and tried to prevent the kind of backlash Denmark suffered over the Prophet cartoons.
Prime Minister Jan Peter Balkenende said he was proud of how Dutch Muslim organisations responded to the film but that it was too early to draw conclusions about the international consequences: "There are reasons for continued alertness."
NATO has expressed concern the film could worsen security for foreign forces in Afghanistan, including 1,650 Dutch troops. A Belgian government spokesman said security had been stepped up at Dutch diplomatic missions in the country.
Danish cartoonist Kurt Westergaard objected to the use of his drawing of the Prophet Mohammad, saying it was shown out of context and that he had taken legal action to have it removed.
SITE said responses to the Wilders film on al Ekhlaas and another al-Qaeda affiliated website, al Hesbah, were significantly lower in volume compared to the cartoons uproar.
(Additional reporting by Rotterdam, Amsterdam, Jakarta, Tehran, Islamabad, Aarhus and Brussels bureaux; Writing by Emma Thomasson; Editing by Jon Boyle)