Arrests made as protesters clash at pro-Trump rally in Berkeley

Violence broke out and at least 20 arrests were made in Berkeley on Saturday as supporters and opponents of President Trump clashed in a public display of the deep-seated tensions still roiling the country since the November elections.

The dueling groups gathered at Martin Luther King Jr. Civic Center Park, where hundreds of people on each side were separated by a makeshift orange barrier. Several fights broke out even before the noon start of the pro-Trump rally, and multiple people fired pepper spray into the crowd.

Berkeley police said they arrested 20 people on charges that included assault with a deadly weapon, several other felony assaults and two warrants stemming from investigations into violence that occurred at a similar rally last month. They confiscated items including a stun gun, Mace, knives, bear spray, an ax handle, pepper spray and a can filled with concrete.

“More arrests will be pursued as Berkeley Police review social media and video footage,” department officials said in a statement.

A pro-President Donald Trump protester is treated for chemical irritants as demonstrators for and against Trump face-off on Saturday, April 15, 2017, in Berkeley, Calf. A pro-President Donald Trump protester is treated for chemical irritants as demonstrators for and against Trump face-off on Saturday, April 15, 2017, in Berkeley, Calf. Photo: Noah Berger, Special To The Chronicle Photo: Noah Berger, Special To The Chronicle Image 1 of / 37 Caption Close Arrests made as protesters clash at pro-Trump rally in Berkeley 1 / 37 Back to Gallery

As the protest kicked off, most of the anti-Trump activists emptied onto Allston Way, bordering the park. The pro-Trump demonstrators stayed in the park, where people in the opposing groups threw soda cans, fruit, shoes, bottles and what appeared to be fireworks at each other. Minutes later, the makeshift barrier dividing the sides snapped, and a huge brawl broke out as both sides began punching and kicking each other.

Soon the barrier was re-established and demonstrators once again shouted at each other from a distance.

“You go back to the ’60s,” shouted one man on the pro-Trump side in a live-stream video.

“You go back to the 1400s,” retorted someone on the opposing side.

Trump protesters and anarchists waving red-and-black flags, marched around the park, periodically stopping to clash with the Trump supporters.

Dozens of officers in riot gear monitored the volatile demonstrators and occasionally lined up to block the protesters from moving in certain directions or into the streets. For the most part, however, they kept their distance — an approach local departments have utilized recently to keep heated situations from exploding into riots.

Injured people — many holding ice packs to their faces or flushing pepper spray from their eyes with milk — were ushered away from the crowd by activists who identified themselves as being there for medical support.

At one point, hundreds of pro- and anti-Trump demonstrators marched up Center Street toward Shattuck Avenue, leaving bloody and bruised participants in their wake.

One man clutched his fingers and said he thought they had been broken. Another man, tears streaming down his face, said he had walked into a gas cloud that had been set off in the street and that his eyes were burning. Witnesses said they also had to help one stabbing victim.

Ben Bergquam of Fresno emerged from the crowd with blood streaming down his face. He held a crumpled “Stop Liberal Intolerance” sign in his hand.

“I got hit in the back of the head with some sticks,” he said as another activist wrapped gauze around his wound. “I don’t agree with everything Trump says, but I don’t agree with violence.”

Nearby, others gathered around a man who was lying in the grass, blood flowing from his head.

“He knows his name, he knows what day it is,” a protester said as another called for medical help.

Lincoln Smith, a 45-year-old man who came to show solidarity against Trump, acknowledged that some of the attendees were overly intense, including a woman who had accused him of being a Trump supporter because he was wearing red shoelaces.

“I’m here to support the message that hate speech is not free speech,” Smith said.

Police said 11 people were injured and treated by paramedics from the Berkeley Fire Department. Seven were taken to local hospitals. There appeared to be no injuries to people who were not involved in the event and no reports of damage to downtown businesses, police said.

Somes businesses closed temporarily, and nearby banks boarded put their ATMs. BART closed the Downtown Berkeley Station about 1:20 p.m., citing a “civil disturbance.” It reopened at about 4:30 p.m.

Inside the park, the pro-Trump rally continued around a makeshift stage where speakers addressed a crowd of dozens waving American flags and wearing red “Make America Great Again” hats.

The rally follows violent eruptions at other recent conservative or pro-Trump events in Berkeley. In March, 10 people were arrested and many others bloodied and bruised as fistfights broke out between marchers and counterprotesters, including crowds of masked anarchists, at a rally supporting Trump at Civic Center Park. In February, a violent protest forced the cancellation of a speech at UC Berkeley by right-wing provocateur Milo Yiannopoulos.

Concern that Saturday’s rally could turn similarly bloody led to the cancellation of the weekly farmers’ market next to Civic Center Park, marking the first non-weather-related shutdown of the popular event in 30 years.

The market’s executive director, Martin Bourque, criticized the rally beforehand as likely to accomplish little more than “shouting matches and bloodshed.”

The demonstration, billed as a peaceful, free-speech rally marking Patriots Day, was organized by a loose collective of conservative and pro-Trump groups.

Speakers included Lauren Southern, a Canadian activist who has said rape affects men more than women, and AltRight.com writer Brittany Pettibone, who has said she believes in Pizzagate, a discredited conspiracy theory involving Hillary Clinton.

At the Saturday rally, Southern told Berkeleyside, a local online news site, that people should “stop supporting antifa,” using a slang term for “antifascist.”

“You see them all over the media saying, ‘Should we punch Nazis? Yes, we should punch Nazis,’ when their interpretation of Nazi is anyone to the right of Marx,” she said, adding: “I totally support progressive free speech 100 percent.”

Several liberal groups organized the counterprotest in the park, promising to shut down the pro-Trump event.

Defend the Bay, a group that says it opposes the “alt-right” white nationalist movement, had suggested that protesters bring food to share, along with a mask or other covering to conceal their identity from police.

Chronicle staff writer Jenna Lyons contributed to this report.

Cynthia Dizikes is a San Francisco Chronicle staff writer. Email: cdizikes@sfchronicle.com Twitter: @cdizikes