Gus Van Sant has won the Cannes film festival's coveted Palme d'Or award for his film Elephant.
The film enters the lives of real-life US students to see how they cope with shootings and violence at school.
Elephantuses non-actor children from Van Sant's home town of Portland, Oregon, to paint an impressionistic picture of everyday high school life that turns suddenly to tragedy.
It comes a year after Michael Moore was lauded at Cannes for his documentary Bowling for Columbine, which also examined America's gun culture and high-school shootings.
Festival watchers, who had their money on Lars von Trier's film Dogvillewinning the top award, were surprised when the maverick Dane and his leading lady, Nicole Kidman, won nothing.
Cannes retained its reputation for favouring intellectual world cinema by giving two awards to Turkish film Uzak(Distant), a moving study of how a man's home life is upset when a jobless cousin moves in.
Director Nuri Bilge Ceylan won the runner-up Grand Prix, and Uzak'stwo main actors - Muzaffer Ozdemir and Mehmet Emin Toprak - jointly won best actor, an honour that goes posthumously to Toprak, Ceylan's cousin, after he died in a car accident the day after learning Uzakhad been selected for Cannes.
Young Iranian director Samira Makhmalbaf received the Jury Award for her film about life in Afghanistan since the Taliban.