Festival president Dieter Kosslick was at the opening

About 500 demonstrators angered by cuts in Berlin's education budget tried to force their way on to the red carpet in Marlene Dietrich Square.

Actors absent from the festival launch included Nicole Kidman, Jude Law and Renee Zellweger - stars of its opening film, US civil war drama Cold Mountain.

The 54th annual festival, featuring 400 films in all, runs until 15 February.

Among the world's most prestigious industry gatherings, it is the first major movie competition of 2004.

Fargo actress Frances McDormand is chairing the film jury

Fargo actress Frances McDormand, who is chairing the festival jury, said she saw no harm in the protests.

"I love that, that's fabulous. We are the people," she said as she arrived to the whistles and chants of the students.

But festival president Dieter Kosslick criticised protesters who he said had thrown unidentified items.

"That's stupid," he said. "The foreign guests won't understand what it is about, they will think we are rioters throwing things."

A screening of Cold Mountain had been expected to draw the stars, but crowds were left disappointed.

Kidman was in Australia for "personal reasons", while Zellweger and Law - both nominated for Oscars - could not get out of filming schedules.

Jack Nicholson and Diane Keaton star in Something's Gotta Give

But Miramax co-chairman Harvey Weinstein promised that Zellweger and Law would make an appearance later in the festival.

Cold Mountain director Anthony Minghella rejected criticism from some US commentators that a film about American history had been shot in Romania to save money.

He dismissed arguments that foreigners had tampered with US history or cheated Hollywood workers out of jobs with the big budget movie.

Big names expected at this year's festival include Jack Nicholson, Cate Blanchett, Juliette Binoche, Julie Delpy, Peter Fonda, Robin Williams, Woody Harrelson and Ethan Hawke.

Oscar-nominated actress Diane Keaton arrived to promote romantic comedy Something's Gotta Give which co-stars Nicholson.