COSTA MESA, Calif. — 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.

Dozens of protesters were mostly peaceful Thursday during the speech. Late in the evening, however, the demonstration grew rowdy 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 Pacific Amphitheatre’s marquee.

Dozens of cars — including those of Trump supporters trying to leave — were stuck in the street as several hundred demonstrators blocked the road, waved Mexican flags and posed for selfies.

Police in riot gear and on horseback pushed the crowd back and away from the venue. There were no major injuries and police did not use any force. The crowd began dispersing about three hours after the speech ended.

Earlier in the evening, a half-dozen anti-Trump protesters taunted those waiting to get into the venue. Trump supporters surrounded one man who waved a Mexican flag and shouted “Build that wall! Build that wall!” — a reference to Trump’s call to create a barrier between the United States and Mexico to stop illegal border crossings.

At one point, seven shirtless women wearing Bernie Sanders stickers over their breasts entered the square outside the amphitheater. They said they were protesting Trump’s lack of engagement on issues of gender equality and women’s rights.

“I feel like he wants to make America great again, but certainly not for women, for the LBGTQ community or for the lower class,” said one of the women, Tiernan Hebron, referencing the lesbian, gay, bisexual and transgender community. “He has, like, done nothing to help with gender equality or women’s rights or reproductive rights or anything.”