Violent outbursts marked a tense day of demonstrations today in Martin Luther King Jr. Civic Center Park as police grappled with controlling the crowd and keeping the peace.

Counter-protesters jumped over barricades into the park after police abandoned the area in the face of hundreds of counter-protesters, including a large black bloc.

At least 13 arrests have been made, according to Berkeley Police Chief Andrew Greenwood.

Police withdrew from the park into the nearby Ronald Tsukamoto Public Safety Building as protesters, organized in a black bloc, chanted “cops and Klan, hand in hand.” Police used some pepper-spray to defend the building.

Joey Gibson, the leader of the right-wing group Patriot Prayer, made an appearance at the park but was chased by counter-protesters soon before being detained by Berkeley Police for his own safety according to the San Francisco Chronicle.

The Berkeley Police Department was bolstered by the California Highway Patrol. Both units donned full riot-gear and brandished non-lethal weapons. The crowd demanded police lay down their arms after one officer chambered a non-lethal round in view of the animated mass.

Several smoke grenades were thrown into the park but did little to disturb the police, who wore gas masks.

The counter-protests, despite sporadic violence and constant tension, were largely peaceful.

W. Kamau Bell, comedian and television host, addressed the crowd from the back of a speaker-laden truck in front of Martin Luther King Jr. Civic Center Park.

“We should be talking out for all the oppressed people when the Nazis don’t show up,” he told the crowd. “Don’t wait for the Nazis, be good all the time everybody.”

Far-right protesters were scarce and didn’t remain in the park long. Some were escorted out by police to avoid conflict.

After declaring victory, the march moved from Martin Luther King Jr. Civic Center Park to nearby Ohlone Park, where the anti-fascist group known as “Antifa” had initially gathered earlier in the day. Protesters have since disbanded.