The violence "spilled onto the streets and it resulted in vandalism and damages of local businesses and some people getting hurt in our community,” Arreguin said in an interview Monday, after he criticized UC Berkeley officials for failing to prepare better for that event.
The mayor said he's concerned about a repeat of that episode in the wake of violence that erupted Sunday after a planned rally by right-wing activists sparked a massive counterprotest.
The "No to Marxism" rally drew only a handful of attendees to Berkeley's Civic Center Park after organizer Amber Cummings called it off. The counterprotest attracted more than 7,000 people, by Arreguin's estimate, who for the most part gathered and marched peacefully.
Arreguin acknowledged the counterprotest was mostly calm, with demonstrators singing, dancing and chanting. But what he called "a small group of extremists" caused violence, with some journalists threatened and right-wing protesters attacked.
“They came in here with the intent on committing violence and mayhem. They wanted to physically confront conservatives,” said Arreguin of the group of black-clad militants.
The Berkeley Police Department reported that there were six injuries and 13 arrests for a variety of charges, including assault with a deadly weapon.
Arreguin said he doesn’t want any more violence in Berkeley from either the far right or far left.
But if Yiannopoulos's planned talk goes forward, he said he'd like to sit down with the university to discuss strategic plans to combat violence.
“I obviously believe in freedom of speech, but there is a line between freedom of speech and then posing a risk to public safety,” Arreguin told the San Francisco Chronicle. “That is where we have to really be very careful — that while protecting people’s free speech rights, we are not putting our citizens in a potentially dangerous situation and costing the city hundreds of thousands of dollars fixing the windows of businesses.”
UC Berkeley officials say they'll work with the city to address safety issues -- and emphasized speakers have not been invited by the university itself.
"We appreciate and understand the mayor’s concerns, and the university will continue to work in close concert with the city in support of our shared commitment to the safety of our communities," Cal spokesman Dan Mogulof said in a statement Wednesday. "We do want to make clear that the university did not 'invite' any of the speakers in question. Rather they are being hosted by registered student organizations that are legally independent from the campus. We have neither the legal right or ability to interfere with or cancel their invitations based on the perspectives and beliefs of the speakers. Where we do have discretion is around everything that has to do with the safety of our communities, and the well-being of those who may feel threatened or harmed by what some of these speakers may espouse. We can assure you that those priorities, along with our commitment to free speech, remain at the center of our planning and preparations."
This story was updated to include UC Berkeley's response to Mayor Arreguin's concerns.