Berkeley Mayor Jesse Arreguin urged UC Berkeley to call off its upcoming conservative "free speech week" event to avoid more turmoil in the city following a conservative rally Sunday that turned violent, according to a report.

"I don't want Berkeley being used as a punching bag," Arreguin told the San Francisco Chronicle.

"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."

"Free speech week" was organized by a right-winged student organization called the Berkeley Patriot, and so far the group has invited conservative provacateur Milo Yiannopoulos, author Ann Coulter, and former White House chief strategist Steve Bannon to speak at the late-September event. Both Yiannopoulos and Coulter had events cancelled this year following violent protests that caused the campus substantial damage.

"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, referring to left-wing demonstrators, commonly called "antifa," who don black attire.

Antifa protesters wearing black clothing clashed with right-wing demonstrators at an anti-hate rally in Berkeley on Sunday.

Following "lots of requests" to deny the club its right to invite the controversial right-winged speakers, UC Berkeley Chancellor Carol Christ released a statement to the student body last week reiterating the university's commitment to free speech.

"The university has the responsibility to provide safety and security for its community and guests, and we will invest the necessary resources to achieve that goal," Christ said.

"If you choose to protest, do so peacefully. That is your right, and we will defend it with vigor. We will not tolerate violence, and we will hold anyone accountable who engages in it."