SAN FRANCISCO -- Milo Yiannopoulos announced he is planning to hold a rally Sunday at the University of California, Berkeley, after a student group who planned a week of events with him pulled out, leading the school to announce the event was cancelled.

The announcement only added to a confusing back-and-forth about the "Free Speech Week" event featuring right-wing firebrands. Yiannopoulos canceled a planned news conference on San Francisco's Treasure Island and instead made the announcement in a live video on Facebook while railing against UC Berkeley.

He said they are "determined to speak" on Sunday, "no matter what."

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Berkeley's reputation as a liberal stronghold and the birthplace of the 1960s Free Speech Movement has made the city and campus flashpoints for the country's political divisions since the election of President Trump. Since February, four political demonstrations have turned violent with masked anarchists rioting on campus.

The Berkeley Patriot student organization, which had organized "Free Speech Week," told university administrators Saturday that their planned four-day event scheduled to start Sunday had been canceled, the university said. Yiannopoulos said he was blindsided and "personally irritated" by that announcement. But he vowed to hold a rally with fellow right-wing commentators at noon on Sunday on Sproul Plaza.

Although the student organization pulled out, "we will not be deterred; we will not be turned away," Yiannopoulos said. "We are going to be hosting an event, come hell or high water tomorrow," he said.

University officials said they had worked around-the-clock and spent more than $1 million to ensure there would be adequate security for the "Free Speech Week" events.

"Claims that this is somehow the outcome desired by the campus are without basis in fact," UC Berkeley spokesman Dan Mogulof said. "The University was prepared to do whatever was necessary to support the First Amendment rights of the student organization."

Over the last few days, student bulletin boards on Sproul Plaza were papered with fliers calling on counter-protesters to "Shut Down Milo Yiannopoulos," saying his brand of inflammatory speech against Muslims, immigrants, women and transgender people was hateful and should not be allowed. The fliers advised supporters to bring bandanas to cover their faces in case police fire tear gas.

Several hundred people gathered on the streets in Berkeley Saturday for an unrelated rally and march against white supremacy, dubbed "No Hate in the Bay." They chanted "say it loud, say it clear, Nazis are not welcome here." One group carried a large banner that read "An injury to one is an injury to all."