COSTA MESA, Calif. (AP): Raucous protesters and supporters of Donald Trump violently confronted each other in California leading to some 20 arrests as the Republican presidential contender brought his campaign to conservative Orange County after sweeping the Northeast GOP primaries.

Dozens of protesters were mostly peaceful Thursday as Trump gave his speech inside the Pacific Amphitheatre. After the event, however, the demonstration grew rowdy late in the evening and spilled into the streets.

Approximately 20 people were arrested by Costa Mesa police, according to a tweet from the Orange County Sheriff’s Department. One Trump supporter had his face bloodied in a scuffle as he tried to drive out of the arena. One man jumped on a police car, leaving its front and rear windows smashed and the top dented in and other protests sprayed graffiti on a police car and the venue’s marquee.