Officers sealed off the section of Hollywood Boulevard, which attracts millions of tourists every year to see the glitter of Tinsel Town including the world-famous Walk of Fame celebrity stars.
By the end of the evening Los Angeles Police Department (LAPD) spokeswoman Karen Rayner said the unrest was winding down. Two people were arrested on suspicion of vandalism, and three police cars were damaged, she said.
Insomniac Inc., which organized the screening of the film about a dance music festival in southern California, said it was "disappointed that a small group of people would try to mar a private documentary screening,'' said the LA Times.
The crowds have vandalized police cars and set fires, Rayner said.
Officials have closed Hollywood Boulevard between Highland and Orange Avenue, Rayner says.
The Hollywood and Highland Metro Red Line station has been closed and Hollywood Boulevard buses are being detoured to Highland and La Brea avenues and Sunset Boulevard, Metro announced.
- AFP