Independent Journal Review reported that police were instructed to use "non-lethal tactics" for crowd control.
At least 20 arrests were made during Saturday's protest, SF Gate noted. More than a dozen people were arrested after fistfights broke out at a park where supporters and opponents of President Trump had gathered.
This comes as thousands of other protesters gathered in cities across the country to pressure Trump to release his tax returns on Saturday which coincided with the deadline for USA tax filings.
According to Berkeley Police Officer Byron White, the rally started on Saturday with an event called "Patriots Day", created online by pro-Trump demonstrators. The police seized numerous prohibited items, including sticks and knives, according to the agency. To protest a speech by conservative media personality Milo Yiannopoulos, rioters took to violence and destruction of the campus. "They believe in freedom, they're libertarians, they believe they shouldn't be attacked", Trump supporter Ossian Morris said.
In March, a pro-Trump rally in Berkeley, again turned bloody when Trump detractors beat and pepper-sprayed supporters. Opposing groups quickly organised their own event. He said the sign "means we're sick of living under neocon rule".
Last month, 10 people were arrested and seven others injured at what was supposed to be a pro-Trump rally in the famously liberal community.
Condolences are pouring in for retired National Football League player Todd Heap and his family after police say the former Pro Bowl tight end accidentally ran over his 3-year-old daughter with a truck, killing her. After Trump supporters said they would hold a "Patriot Day" rally, counter-protesters chose to hold a rally at the same place.
Part of the demonstration crowd moved to Shattuck Avenue and Center Street, and these roads were blocked off. City officials had shut down a farmers market in the park in anticipation of Saturday's rally, and warned against vandalism and violence.
"We're really against what Trump is doing to our country". Democratic Rep. Maxine Waters, of California, said there's nothing to prevent Trump from releasing his income taxes and that "the simple truth is he's got a lot to hide". Organizers for Tax March San Francisco discovered the chicken and re-dubbed it "Chicken Don" to poke fun at the President for being too afraid to release his tax returns.