Story highlights Protesters took to the streets following a Trump rally in Costa Mesa

At least one Trump supporter was visibly bloodied after being punched in the face

Costa Mesa, California (CNN) Scores of protesters took to the streets Thursday night outside a Donald Trump campaign event here, drawing out police officers in riot and tactical gear and on horseback who sought to disperse the crowd.

The crowd gathered in the streets outside the OC Fair & Event Center as Trump addressed several thousand supporters at the Center's amphitheater. At least one police car was damaged and several scuffles broke out amid the hectic scene.

Protesters blocked a main intersection, impeding traffic, and officers with the Orange County Sheriff's Department and Costa Mesa Police Department worked to disperse the crowd, ordering protesters out of the streets.

About 20 people were arrested, the Orange County Sheriff's Department tweeted late Thursday night after the protests had cleared.

#OCSDPIO Post Trump Rally Protest over. Approx 20 arrests by Costa Mesa PD. No major injuries. Crowd dispersed by 11pm. No further updates — OC Sheriff, CA (@OCSD) April 29, 2016

Lt. Mark Stichter, the Sheriff's Department's public information officer, could not provide an official estimate on the number of protesters, but demonstrators could be seen filling the intersection of Fairview Road and Fair Drive.

Read More