SAN FRANCISCO >> Right-wing provocateur Milo Yiannopoulos vowed today to hold a rally at the University of California, Berkeley after a student group that planned a week of events with him called it off.

His announcement only added to a confusing turn of events surrounding “Free Speech Week,” a four-day campus event slated to begin Sunday featuring right-wing firebrands.

The conservative student group Berkeley Patriot, which had been organizing the event, told university administrators today that they would cancel it, the university said. The group’s representatives told the San Francisco Chronicle they feared for their safety.

“It is extremely unfortunate that this announcement was made at the last minute, even as the University was in the process of spending significant sums of money and preparing for substantial disruption of campus life in order to provide the needed security for these events,” UC Berkeley spokesman Dan Mogulof said in a statement.

Yiannopoulos said he was blindsided and “personally irritated” by the news, but he insisted on holding a rally with fellow right-wing commentators Sunday on Sproul Plaza, the center of activity on campus during the 1960s Free Speech Movement.

“We are going to be hosting an event come hell or high water tomorrow,” Yiannopoulos said in a live video on Facebook. He made his comments from a hotel room after cancelling a news conference on San Francisco’s Treasure Island.

“We will be expressing our constitutional rights to free speech, free expression, on Sproul Plaza, the home of the Free Speech Movement, tomorrow as planned, with or without student help, with or without the cooperation of UC Berkeley itself.”

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.

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

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

Campus police Chief Margo Bennett said authorities were “going to be prepared and handle things that may happen when a speaker can just show up.” She said anyone can come to the open plaza to speak, but they can’t use amplified sound without permission or interfere with the business of the university.

Her address to the media this afternoon was halted by a demonstrator who railed against the “Fascist assault” on the university and announced a counter protest against Yiannopoulos on Sunday.

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 bandannas to cover their faces in case police fire tear gas.

In anticipation of Free Speech Week, several hundred people marched on the streets of Berkeley to Sproul Plaza today in a protest dubbed “No Hate in the Bay.” They chanted “say it loud, say it clear, Nazis are not welcome here” and halted traffic at several blocked intersections.

Speakers included Chelsea Manning, the 29-year-old transgender woman known as Bradley Manning when she was convicted in 2013 of leaking a trove of classified documents.

One group carried a large banner that read “An injury to one is an injury to all.”