A fire burns on UC Berkeley's Sproul Plaza during protest against a scheduled appearance on Feb. 1, 2017 by conservative commentator Milo Yiannopolous. (Brittany Hosea-Small/UC Berkeley)
Updated Feb. 6, 11:40 a.m.
UC Berkeley could have done a better job in preparing for the violent protests that led to the cancellation of an on-campus speech by Breitbart News commentator Milo Yiannopoulos Wednesday, according to Berkeley's mayor and the union that represents university police officers.
The protest against Yiannopoulos, the right-wing provocateur criticized for racist, misogynist, anti-transgender and white supremacist statements, caused about $100,000 in damage to campus property and led to the vandalism of more than a dozen businesses in downtown Berkeley and along Telegraph Avenue.
"In the end, this was a decision that I didn't make, that the City Council didn't make. This was a decision of the university," Berkeley Mayor Jesse Arreguin said in an interview.
"I think the university should have consulted with the city before they made the decision to invite this person to the campus," Arreguin said. "There should have been some serious consideration about whether he should have been invited to begin with, given the fact that he's provoked a violent response on other campuses."
UC Berkeley spokesman Dan Mogulof said police actions the night of the protest conformed to findings and recommendations from a report issued after protests on UC Berkeley and Davis campuses in 2011.
UC police were in touch with Berkeley city police about the event well before Wednesday night, Mogulof said.
The demonstrations involved more than a thousand protesters. Campus officials say police and the university could not have anticipated that some of them would "invade" the campus to shut down the Yiannopoulos event.
The campus police department has launched an investigation into Wednesday night's violence. UC Berkeley officials say about 150 masked individuals hurled Molotov cocktails, set fires and pushed barricades into windows.
Nine people were treated for injuries at Alta Bates Summit Medical Center over a two-day period, and three men were arrested in connection with the protest.
The union that represents UC police says there wasn't a good tactical plan in place beforehand.
"They were unable to assist the citizens and the public that were out there that were defenseless against these rioters, who were actively engaging in breaking the law and attacking defenseless citizens," said John Bakhit, an attorney who represents the Federated University Police Officers Association.
Bakhit said in an interview that UC Berkeley police officers were ordered not to take any enforcement action against protesters who lit fires and threw rocks, bottles and fireworks at them. He said there weren't enough officers on hand at the start of the protests to make arrests and protect the public.
"When these rioters saw that there was no action taken against them, it emboldened them into acting more aggressively," Bakhit said.
Campus officials would not comment on the union's criticism, but Mogulof said that civilian university staff does not interfere in law enforcement decisions.
"The violence was an attack on our fundamental values, which are maintaining and nurturing open inquiry and an inclusive, civil society -- the bedrock of a genuinely democratic nation," Dirks said in a statement. "We are now, and will remain in the future, committed to Free Speech not only as a vital component of our campus identity, but as essential to our educational mission."
Hours after the protest, President Donald Trump suggested possible cuts to federal funding for UC Berkeley in a tweet that prompted sharp criticism from Rep. Barbara Lee, whose district includes Berkeley.
KQED's Sukey Lewis and Devin Katayama contributed reporting to this story.