Violence has broken out between left- and right-wing protesters, after more than 100 black-clad masked antifa broke through police barricades at a ‘Rally Against Hate’ and assaulted at least four, including the leader of a pro-Trump conservative group.

At least ten arrests were made on Sunday in Berkeley, California after the left-wing ‘Rally Against Hate’ confronted a handful of right-wing protesters at a ‘No To Marxism In America’ rally. Antifa is short for ‘anti-fascists’.

The arrest charges in the skirmishes at Civic Center Park were various but included assault and violating a prohibition on wearing masks, KCRA reported.

Several thousand joined in the left-wing ‘Rally Against Hate’, intended as a counter-protest to the right-wing ‘No To Marxism In America Event’, which was officially cancelled after organizers said they had concerns of violence.

A handful of people wearing shirts and signs in support of President Donald Trump did turn up, however, and were quickly surrounded by the ‘Rally Against Hate’ marchers. Several Trump supporters sought police escorts out of the area. 

A group of more than 100 masked antifa, with shields emblazoned with the words ‘no hate’ and waving a flag identifying themselves as anarchists, then broke through police barricades, avoiding security checks by officers to take away possible weapons.

Then the antifa blended in with a crowd of 2,000 largely peaceful protesters who turned up to demonstrate in the ‘Rally Against Hate’.

Among those assaulted by antifa was Joey Gibson, the leader of the pro-Trump Patriot Prayer group.

Gibson had canceled a separate rally Friday and was prevented from holding a news conference on Saturday when authorities closed off the public square he planned to use.

The activist has said he launched Patriot Prayer after several supporters of President Trump were beaten at a Trump campaign stop in San Jose, California last year.

After the antifa spotted Gibson at the Berkeley park, they pepper-sprayed him and chased him out of it as he backed away with his hands held in the air, escorted by a masked man wearing football shoulder pads.

Gibson and the man retreated behind a line of police wearing riot gear, who set off a smoke bomb to drive away the anarchists.

Earlier in the day, another group of left-wing demonstrators dressed in black attacked at least three men in the park, kicking and punching them until the assaults were stopped by police. Police also used a smoke grenade to stop one scuffle.

Police in the San Francisco area have been braced for violence and trying to prevent protests that draw left-wing and right-wing opponents since the deadly confrontation in Charlottesville, Virginia, on August 12 during a rally of white nationalists.

Berkeley authorities did not issue a permit for Sunday’s gathering of right-wing protesters and Berkeley Mayor Jesse Arreguin had urged counter-protesters to stay away.

The ‘No To Marxism In America’ rally had been canceled by organizer Amber Cummings, who encouraged supporters to stay away but said she would attend on her own.

By mid-afternoon Cummings had not appeared and left-wing protesters far outnumbered right-wing supporters.

Earlier in the day, police had set up barricades around park and checked people who entered to make sure they did not have prohibited items like baseball bats, dogs, skateboards and scarves or bandanas they could use to cover their faces.

Several people were arrested for violating rules against covering their faces or carrying items banned by authorities.

At one point, a left-wing protester denounced a Latino man holding a ‘God Bless Donald Trump’ sign.

‘You are an immigrant,’ said Karla Fonseca. ‘You should be ashamed of yourself.’

Several other people also yelled at the man, who said he was born in Mexico but supports Trump’s proposal to build a wall along the southern border.

Police pulled one supporter of President Donald Trump out of the park over a wall by his shirt as a crowd of about two dozen counter demonstrators surrounded him and chanted ‘Nazi go home’ and pushed him toward the edge of the park.

At least two people were detained by officers for wearing bandannas covering their faces.

Anti-rally protesters chanted slogans ‘No Trump. No KKK. No fascist USA’ and carried signs that said: ‘Berkeley Stands United Against Hate’.

A separate group of counter protesters had assembled earlier Sunday at the nearby University of California, Berkeley campus and then marched park to merge with the anti-rally protesters who had already gathered there.

Both Cummings and Gibson have disavowed racism and say they wanted to hold the rallies to bring conservative voices to the liberal San Francisco Bay Area.

Student activism was born during the 1960s free-speech movement at Berkeley, when thousands of students at the university mobilized to demand that the school drop its ban on political activism.

However, the violence in Charlottesville led San Francisco area police and civil leaders to rethink their response to protests.