By Ann Saphir
BERKELEY, Calif. (Reuters) - Police at the University of California at Berkeley braced on Thursday for potential civil unrest stemming from a now-canceled speaking engagement by conservative commentator Ann Coulter following a recent spate of politically charged violence on or near the campus.
Coulter, one of America's best-known and most provocative pundits on the political right, said on Wednesday that she no longer intended to defy university officials by addressing UC Berkeley students on campus this week.
But she left open the possibility of paying a visit to her supporters at the school, long a bastion of liberal student activism and a center of the Free Speech Movement protests of the 1960s.
Campus police Captain Alex Yao said his department would maintain "a highly visible presence," pointing to continued threats of violent protests by Coulter supporters and opponents.
Berkeley city police also issued a notice that local law enforcement was on alert for any protests that turned unruly.
"Berkeley police and allied agencies are working cooperatively to ensure the safety of attendees while arresting those who commit violence or other crimes," the notice said.
Social media feeds of militant left-wing and right-wing activists remained abuzz with vows to proceed with demonstrations and counter-demonstrations.
As of noon, a peaceful crowd of roughly 100 people, some carrying American flags, some wearing helmets, had congregated in downtown Berkeley at a public square ahead of demonstrations expected later in the day. About a dozen police officers stood nearby, batons and helmets dangling from their belts.
"We're here for peace," said David Fry, a resident of Tacoma, Washington, and head of the American Freedom Motorcycle Association. "I expect free speech to happen."
Campus and local authorities said they were taking the potential for lawlessness seriously following several episodes of politically fueled disturbances.
In February, protesters opposed to an appearance by Milo Yiannopoulos, then a senior editor for the conservative Breitbart News website, set fires, broke windows and clashed with police on campus, prompting cancellation of his speech.
And in March and again in April, opposing groups from the far-right and far-left skirmished violently near campus.
UC Berkeley Chancellor Nicholas Dirks cited all three incidents in explaining why the school balked at Coulter's original plans to speak on campus on Thursday.
University officials said organizers erred by inviting Coulter without notifying campus officials in advance, as is required of all student groups, and by failing to submit to a "security assessment" to determine a suitable venue for the event. UC Berkeley officials denied that Coulter was unwelcome because of her politics.
After initially barring a Coulter speech for Thursday, university officials proposed moving the event to next Tuesday. Coulter said she could not make it then and accused the school of trying to limit her audience by choosing a date that fell in a study week ahead of final exams.
Coulter then insisted she would go through with her speech on Thursday, despite university objections. But she changed her mind after student organizers withdrew their invitation, though they vowed to press ahead with a lawsuit filed on Tuesday accusing UC Berkeley of suppressing freedom of speech.
(Additional reporting by Noel Randewich in San Francisco; Mark Hosenball in Washington and Jonathan Allen in New York; Writing and additional reporting by Steve Gorman in Los Angeles; Editing by Simon Cameron-Moore and Bill Rigby)