Several fights broke and 14 people were arrested at a "Rally Against Hate" in Berkeley on Sunday afternoon.
The event at Civic Center Park began peacefully with approximately 2,000 counter-protestors showing up in response to a planned right-wing protest.
Concerned about the potential for violence, Berkeley police had banned protesters from covering their faces or carrying a variety of items that could be used as weapons. They also set up barricades around the park with officers checking people's bags and warning them that a long list of items were forbidden — including baseball bats, dogs and skateboards and scarves or bandanas to cover their faces.
But more than 100 protesters dressed in black pushed their way into Civic Center Park.
Several dozen left-wing protesters surrounded a handful of right-wing supporters, then shouted at them and pushed them. The right-wing protesters sought protection from police and were escorted away. Either tear gas or a smoke grenade was reportedly deployed by police during the fight.
The San Francisco Chronicle reports that Joey Gibson, the leader of Patriot Prayer, a right-wing group that organized a rally Saturday in San Francisco, was handcuffed and detained after being pepper-sprayed and chased by a mob of demonstrators.
Hundreds of peaceful demonstrators peeled off and returned to Ohlone Park, according to the San Francisco Chronicle: "The scene at Ohlone Park had been peaceful and celebratory compared with the scene at Civic Center."
Crowds began dispersing around 3 p.m. and by 4 p.m. had mostly gone home.
Counter-protesters largely outnumbered right-wing supporters as the dueling protests began.
Karla Fonseca, holding a sign that said "Together We Stand" yelled at Latino man holding a "God Bless Donald Trump" sign.
"You are an immigrant," she said. "You should be ashamed of yourself."
Several others 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.
The Berkeley rallies happened a day after a rally planned by a right-wing group fizzled amid throngs of counter-protesters in San Francisco. San Francisco Mayor Ed Lee on Saturday declared victory over a group he branded as inviting hate.
Berkeley is the city that gave birth to the 1960s Free Speech Movement but authorities refused to issue a permit allowing Sunday's event. The city and campus have been the site of political clashes and violence over the past year.
Sunday's organizer Amber Cummings, a transgender woman who is a supporter of President Donald Trump, has repeatedly denounced racism. Cummings canceled her event — saying that demonization by mayors in both cities and left-wing extremists made it impossible to speak out.
Cummings said she would be the sole attendee — but several supporters turned up anyway.
Berkeley Mayor Jesse Arreguin urged counter-protesters to stay away.
Cummings has said on social media and in media interviews that Marxism is the real evil and that members of the anti-fascist movement are terrorists.
"I'm not safe to walk down the road with an American flag in this country," she said to reporters in Berkeley last week.
Saturday's event was organized by a group known as Patriot Prayer. Its leader Joey Gibson has also repeatedly disavowed racism. Asked Saturday whether he had any plans to go to Berkeley, Gibson, the leader of Patriot Prayer, said he would "analyze the situation."
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 deadly confrontation in Charlottesville, Virginia, on Aug. 12 during a rally of white supremacists led San Francisco police and civil leaders to rethink their response to protests.
Associated Press writers Jocelyn Gecker, Janie Har and Sudhin Thanawala in San Francisco contributed to this report.