Thousands gathered Sunday in response to a planned anti-Marxism protest that was canceled amid concerns demonstrators might be attacked. The counter-demonstration was largely peaceful for several hours until the Antifa overran police barricades around the protest area. The violence was swift but brief, and among those targeted was Joey Gibson, leader of the right-wing organization Patriot Prayer that had called off a demonstration a day earlier in San Francisco for security reasons. Berkeley Police Chief Andrew Greenwood said officers were told not to actively confront the anarchists. Several dozen people were injured and at least two have been hospitalized. One officer was injured while making an arrest and several others were hit with paint.

There were 13 arrests on various charges including, assault with a deadly weapon.

"The potential use of force became very problematic" given the thousands of peaceful protesters in the park, Greenwood said. Once anarchists arrived, it was clear there would not be dueling protests between left and right, so he ordered his officers out of the park and allowed the anarchists to march in.

There was "no need for a confrontation over a grass patch," Greenwood said. Later, the actions of police leadership were criticized by the organizers of the rallies, saying that police failed to protect their 1st amendment rights against Antifa.

Several hours later, the demonstration broke up without any further incidents.

Officials in Berkeley and San Francisco had been girding for the possibility of violent clashes at pro and anti-Trump demonstrations, but Saturday's in San Francisco by Patriot Prayer was called off, and police blocked access to a public square where Gibson had planned to hold a news conference. He instead held it outside the city and criticized police for not doing enough to ensure supporters' safety at the originally scheduled location of Crissy Field. Still hundreds of counter-protesters marched through the city. San Francisco Police Chief Bill Scott said Saturday that police made a single arrest for public intoxication during demonstrations organized by left-wing groups.

The anti-Marxist rally in Berkeley was organized by Amber Cummings, a transsexual supporter of Trump. Citing the potential for violence, she canceled the event but said she would show up on her own. She was not seen there, though Gibson vowed to come, and when he did, anarchists assaulted him.

They pepper-sprayed him and chased him as he backed away with his hands held in the air. Gibson rushed behind a line of police wearing riot gear, who set off a smoke bomb to drive away the attackers. Separately, groups of hooded, black-clad protesters attacked at least four other men in or near the park, kicking and punching them until the assaults were stopped by police. The assaults were witnessed by an Associated Press reporter. At one point, an anti-rally protester denounced a Latino man holding a "God Bless Donald Trump" sign.

"You are an immigrant," Karla Fonseca said. "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 border. Several Americans of central and south-American origin support Trump's immigration plans, so as not to compete with the cheap labor of illegal immigration.

Police pulled one supporter of Trump out of the park over a wall by his shirt as a crowd of about two dozen Antifa 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. Meantime, newly appointed University of California, Berkeley Chancellor Carol Christ said the campus was "working very hard on the security arrangements" for the Sept. 14 appearance of conservative commentator Ben Shapiro. Campus officials will add more police to the event than were present for the scheduled appearance of another conservative, Milo Yiannopoulos, Christ said. That planned talk was canceled when demonstrations turned violent and burned down campus property in February.

As Antifa grows more and more violent, not only in the US but also in Europe, as evidenced by the July G20 riots in Hamburg, the calls to declare it a terrorist organization have grown louder and louder. The State of New Jersey has already done so. There are dozens of videos on YouTube showing Antifa members singling out Trump supporters and beating them to the ground.