Director Fatih Akin (R) and actor Tahar Rahim Photo: CFP

The race for the Golden Lion in Venice took a dark turn on Sunday with stories of war and genocide including an ambitious tale that has drawn death threats for German-Turkish filmmaker Fatih Akin.

The mass murder of Armenians by the Ottomans in 1915 is the theme of Akin's latest film The Cut - a hugely controversial subject particularly in Turkey and one that has sparked a violent reaction from extremist groups.

"I had seven or eight years to prepare myself for the reaction to the film, it's something I'm not surprised by. For art it's worth to die," he told journalists in English in Venice, adding that he tries "not to take it too seriously."

In the film an Armenian blacksmith (played by French actor Tahar Rahim) is separated from his wife and two young children in what is present-day Turkey when the Ottomans join World War I, and he is called up for military service.

The brutal slaughter of Armenians and the flight of survivors to far-flung lands are evoked in gut-wrenching scenes, only slightly let down by a drop-off in emotional intensity in the film's second half.

The film's co-writer Mardik Martin, who worked with Martin Scorsese on such classics as Raging Bull and Mean Streets, told Venice he'd come out of retirement for The Cut because it tackled a historical event barely addressed in cinema.

"Hitler said 'Why not kill Jews? The Armenians were annihilated in the First World War and nobody said anything about it'," the 77-year-old said.

"Which just goes to show, if you don't say anything about genocide, we don't learn anything," said Martin, who was raised in Baghdad in an Armenian family.

Up against The Cut for Venice's top prize is Far From Men, a tale of honor and friendship set at the start of the Algerian war of independence.