BERKELEY, Calif. (BCN) - As violence escalates, police are advising the public to avoid the area around the "No to Marxism" rally at Berkeley's Martin Luther King Jr. Civic Center Park.
Anyone in the park itself should leave immediately, police said.
A group of people surrounded a man and beat him to the ground. About two dozen police officers intervened and carried the man to safety.
"Avoid area bounded by (Martin Luther King Jr. Way), Allston Avenue, Milvia Avenue and Addison Street. If near Civic Center Park, leave immediately," police said in an advisory message.
"There are large crowds converging on Civic Center Park in downtown Berkeley.
Tensions between protesters and counter-protesters are escalating," police said.
The number of arrests has grown to 10, according to police.
A person dressed in black, with a black face mask and black helmet - hallmarks of the infamous Black Bloc, which advocates violence - grabbed at least one attendee's camera and destroyed it.
Among other things, a fistfight took place between two people on Martin Luther King Jr. Way near Allston Avenue.
In one incident observed by a Bay City News Service reporter, a man was chased out of the park and trapped against the wall at a gas station a few blocks away by a group of 35-50 people.
The man was heard saying, "I don't hate blacks, I don't hate Jews," as the group of people screamed at him.
In the wake of the chase, an attendee at the park was seen tearing up a Trump/Pence flag.
Police have been checking people as they arrive at the park for items that could be used as weapons, but a group of people jumped the barricades set up by law enforcement and entered without being checked.
Amber Cummings, the organizer of the event, was denied a permit for the event last week but pressed ahead with the event. She said she would attend, and asked others not to do so.