Berkeley, Calif. Mayor Jesse Arreguin wants the University of California-Berkeley to cancel a "Free Speech Week" event that campus conservatives have planned, fearing more "mayhem" from "antifa" fighters.

A rally on Sunday turned violent when left-wing protesters attacked supporters of President Donald Trump and other conservatives.

Now, Arreguin does not want the "Free Speech Week" event put on by the campus group Berkeley Patriot to meet, arguing their events invited the trouble that has affected the city, the San Francisco Chronicle reports:

"I don't want Berkeley being used as a punching bag," said Arreguin, whose city has been the site of several showdowns this year between, on the one hand, the left and its fringe anarchist wing, and on the other, supporters of President Trump who at times have included white nationalists. "I am concerned about these groups using large protests to create mayhem," Arreguin said. "It's something we have seen in Oakland and in Berkeley." The mayor wants UC Berkeley to halt plans by a conservative campus group, the Berkeley Patriot, to host right-wing provocateur Milo Yiannopoulos during its scheduled Free Speech Week from Sept. 24-27. Berkeley's right-vs.-left cage matches began with an appearance that Yiannopoulos was to have made in February at a campus hall, an event that was aborted when black-clad anarchists like those who broke up Sunday's downtown rally stormed into Sproul Plaza, smashed windows and set bonfires.

The report stated the Berkeley Patriot also wants conservative author Ann Coulter and former White House strategist Steve Bannon to appear for "Free Speech Week." A spokesman for the Berkeley Patriot has said that the logistics of the event are still being worked on and they were working with police and school officials.

"I'm very concerned about Milo Yiannopoulos and Ann Coulter and some of these other right-wing speakers coming to the Berkeley campus, because it's just a target for black bloc to come out and commit mayhem on the Berkeley campus and have that potentially spill out on the street," Arreguin said.

His use of the phrase "black bloc" was a reference to antifa, who dress in black and wear masks.

"I obviously believe in freedom of speech, but there is a line between freedom of speech and then posing a risk to public safety," he said. "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."