Violent protests erupted at the University of California at Berkeley on Wednesday evening after an event featuring an alt right speaker was canceled due to safety concerns after more than 1,000 people showed up outside the campus venue.

Breitbart editor Milo Yiannopoulos was scheduled to address 500 attendees on behalf of the school's Republican club.

"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," the university said in a statement released two hours before the event was slated to begin.

Outside the student union, protesters torched a small cart, causing a sizeable fire that produced a cloud of black smoke. The smoke triggered fire alarms in vicinity buildings to go off. Rioters threw smoke bombs, seen and heard going off behind TV media reporters at the scene.

The campus police were not visible at the scene as the incident continued to escalate, breaking windows of nearby vehicles.

Yiannopoulos supported President Trump during the 2016 election. He was famously banned from Twitter for harassing "Saturday Night Live" actress Leslie Jones.

The speaker called into Fox News' "Hannity" during the riots to say he had left the campus and was safe.