The crowds are thought to have come to Grauman's Chinese Theatre after one of the DJs featured in the film invited his Twitter followers to "a block party" outside the cinema.
Kaskade wrote: "Let's see if the magic of social networking will work today. Today@6pm in Hollywood @Mann's Chinese Theatre. ME+BIG SPEAKERS+MUSIC=BLOCK PARTY!!! RT! (sic)"
He later expressed concerns for people's safety, adding: "Everybody CHILL OUT!!! The cops are freaking out. BE SAFE AND LET'S HAVE SOME FUN!"
He also encouraged people to "be respectful and chill out" as the trouble escalated.
The world premiere of Electric Daisy Carnival Experience and a subsequent after party were both thought to be private, ticket-only events.
Police closed down Hollywood Boulevard between Highland Avenue and Orange Avenue. However, they were met with oppositions from some fans who reportedly began fighting, throwing bottles and climbing on to police cars.
They fired riot bean bag guns into the crowd and the road closures caused traffic jams in the surrounding area.
The Electric Daisy Carnival Experience is based on the electronic music festival of the same name and features live performances from musicians including Moby, David Guetta and Deadmau5.
Screening organisers Insomniac Inc issued a statement expressing disappointment "that a small group of people would try to mar a private documentary screening".
> Moby 'suffers electric shock live on stage'
> More showbiz news
Watch a KTLA news report on the Electric Daisy Carnival Experience premiere disturbance below: