BERKELEY, Calif. -- A large swath of the University of California at Berkeley was shut down Thursday evening as about a thousand protesters gathered outside a speaking event by right-wing author and political commentator Ben Shapiro.
Campus officials had feared that the event could lead to similar violence that has erupted at right wing rallies and events in recent months, including just last month at Martin Luther King Jr. Civic Center Park, where thousands of demonstrators confronted a handful of right-wing activists.
While there were some arrests -- Berkeley police said there were nine -- and some tense moments of confrontation, there was no violence reported. A woman was taken away on a stretcher, but campus officials said she had suffered a medical emergency and was not assaulted.
VIDEO: Who is Ben Shapiro?
Berkeley police said the nine arrestees included four people arrested under city law prohibiting weapons in certain public parks. They were identified as 44-year-old Sara Rourke of San Francisco, 29-year-old Michael Sullivan of Hayward and 44-year-old Eddy Robinson. Hannah Benjamin, 20, of Fremont was also arrested under that law as well as battery on a police officer.
Also arrested were 18-year-old Kerim Celik of Saratoga for disturbing the peace, 24-year-old Noe Gonzalez Gudino of Richmond for disturbing the peace and public intoxication, 21-year-old Miguel Reyes of Colton for resisting arrest, 20-year-old Jorge Cabanillas for battery and 45-year-old Darin Bauer for battery.
The greatest drama came from when a group of about two dozen students staged a protest on a walkway over the entrance to the event, where police were conducting careful screenings of ticket holders. The group hung signs that said, "UC protects fascism, not students," and "trans lives matter here."
The students eventually retreated back into the Martin Luther King Jr. Student Union, where they used tape to write "stolen land" and "f-- Carol" -- directed at UC Berkeley Chancellor Carol Christ for allowing right
wing speakers -- on the windows.
RELATED: UC Berkeley plans extreme security ahead conservative speech event
Eventually police surrounded the room, but the demonstrators made a phone call to the group outside, who blared their conversation over loudspeakers. Students stuck inside said the police wanted them to leave two at a time, but they were fearful of being arrested.
"Let them go," the crowd outside roared, and eventually the police relented and the entire group was allowed to leave.
UC Berkeley police Chief Margo Bennett said that she was relieved the event was held safely and largely lawfully. While the city made several arrests, campus police made none, she said.
The intense security precautions weren't overkill in her eyes, she said, because "we wouldn't have been doing our duty if we didn't look at the worst case scenario."
Campus spokesman Dan Mogulof said there are "no regrets" over shutting down Sproul Plaza, one of the campuses most active and central locations. Given the tense protests that have happened in Berkeley and nationwide recently, it was necessary to devote substantial resources to security, he said.
VIDEO: What to do if you're stopped by police at a rally
The resources included aid from not only city of Berkeley police but officers from the California Highway Patrol and the Alameda County Sheriff's Office, most of whom were in full riot gear throughout the evening.
According to Berkeley police, there was additional aid from Oakland police, agencies in Solano County, The Monterey County Sheriff's Office, Fremont police, Citrus Heights police and Stanford University police.
The cost of putting on the event amounted to an estimated $600,000, Mogulof said.
While there were no reported injuries or property damage in these protests, Berkeley could be the scene of more demonstrations before the month is over as a full slate of conservative speakers have been announced for the so-called "Free Speech Week" beginning Sept. 24.
Right-wing provocateur Milo Yiannopoulos, whose own speaking engagement was canceled amid violent protests in February, has been publicizing the event, announcing a slate of speakers that including himself, Ann Coulter and former White House aid Steve Bannon.
Bennett said she is planning for the event, keeping up on the latest announcements and working to predict what might happen.
But Mogulof stressed that no events publicized have been confirmed, no contract has been obtained for campus venues, no insurance has been purchased and no information has been given to the Police Department.
"Time's running out," he said.
Police are asking the public to submit pics and videos as they investigate crimes committed during Thursday night's protests. Click here for info on how to make a submission.
Click here for a look back at stories and videos about recent protests around the Bay Area.