Protesters hurled smoke bombs, broke windows and started a bonfire prompting University of California at Berkeley officials to cancel a talk Wednesday by a polarizing editor of Breitbart News out of safety concerns.
The decision was made two hours before the appearance of Milo Yiannopoulos (yuh-NAH'-poh-lihs) because a crowd of more than 1,500 had gathered outside the venue, the university said in a statement.
"Of paramount importance this evening was the campus's commitment to ensure the safety and security of those attending the event, the speaker, those who came to engage in lawful protest, as well as members of the public and the Berkeley campus community," it said.
UC Berkeley spokesman Dan Mogulos said there are no immediate reports of arrests or serious injuries.
The 32-year-old right-wing provocateur is a vocal supporter of President Donald Trump and a self-proclaimed internet troll whose comments have been criticized as racist, misogynist, anti-Muslim and white supremacist. He was banned from Twitter after leading a harassment campaign against "Ghostbusters" actress Leslie Jones.
Hundreds of peaceful demonstrators carrying signs that read "Hate Speech Is Not Free Speech" had been protesting for hours before the event. A smaller group of protesters dressed in black and in hooded sweatshirts showed up as night fell and used metal barricades to break windows, threw smoke bombs and flares and used a diesel generator to start a large bonfire outside the building.
Yiannopoulos' visit to Berkeley was sponsored by the campus Republican club. The university has stressed it did not invite him and does not endorse his ideas but is committed to free speech and rejected calls to cancel the event.
"The event has been canceled," Yiannopoulos posted on his Facebook page. "I'll let you know more when the facts become clear. One thing we do know for sure: the Left is absolutely terrified of free speech and will do literally anything to shut it down."
The Berkeley College Republicans said its "constitutional right to free speech was silenced by criminals and thugs."
"Their success is a defeat for civilized society and the free exchange of ideas on college campuses across America," it said in a statement.
Yiannopoulos' talks have sparked protests, shouting matches and occasional violence at stops around the country. A man was shot and wounded at protests outside his Jan. 21 talk at the University of Washington.
Rowdy protests at UC Davis Jan. 13 prompted campus Republicans to cancel his appearance at the last minute. His final stop was supposed to be UCLA on Thursday but the invitation was rescinded, making Berkeley his grand finale.