The "March 4 Trump" rally in Berkeley on Saturday was advertised as a peaceful gathering, but violence broke out before the start of the actual event, and ended in 10 arrests.
A rowdy crowd gathered at the Martin Luther King Jr. Civic Center Park. Supporters and detracters of President Donald Trump, including members of the national group By Any Means Necessary, were joined by a large number of police officers, clad in riot gear.
At first, people toted signs, chanted slogans and got into heated debates. Before long, Trump supporters were fighting counter-protesters and getting in their faces to show support for the president.
Local news from across Southern California
People wearing goggles, motorcycle helmets, gas masks or with their face half-covered with bandanas were pushing each other, throwing punches and hitting each other with the sticks holding their signs. They also pepper sprayed one another, set off smoke bombs and fireworks, and set fire to American flags and "Make America Great Again" caps.
Heated 'March 4 Trump' in Berkeley Ends in Arrests, Injuries
Tito Mena of Stockton attended the rally hoping for a productive discussion between people from both sides of the political aisle.
"We have a right in America to speak our opinions and speak our voice even if some others might think it's wrong," he said. "As long as you're not causing harm to others, I will uphold the right for everyone to speak."
Mena's wishes were crushed. Police officers, who were forced to intervene in several fights, arrested almost a dozen people during the tense rally. They pinned a man to the ground and restrained him when he began to chase after someone with whom he had been fighting, according to social media.
They also took away a man, dressed in shin pads, a helmet and a sweatshirt that said "Basket of Deplorables," from the crowd at the Civic Center Plaza. Officers took away a shield and stick that he was carrying, placed him in handcuffs and ushered him into what looked like an unmarked police cruiser.
Hillary Clinton coined the controversial phrase, while speaking at an LGBT for Hillary Gala in New York City on Sept. 9, 2016. She referred to Trump’s supporters — the so-called "Basket of Deplorables" — as "racist, sexist, homophobic, xenophobic, Islamaphobic."
The skirmishes led to at least three injuries. Officers were caught on camera helping a man, who was bleeding profusely from what appeared to be a head wound.
Videos show Trump protesters chanting, "No Donald Trump, no KKK, no racist, fascist USA," while his backers countered, "Build the wall." Members of the feuding groups were also heard singing the National Anthem and others hurling obscenities at Trump.
Asked whether or not the rally accomplished anything, Melanie Lawrence of Berkeley said the East Bay city "will continue having a reputation for being full of crazy people who love politics."
The 2 p.m. rally was one of dozens planned nationwide to show support for the new president. But it is the only one in the Bay Area and is one of three expected in California.
By 3:30 p.m., marchers had taken to the streets, snarling traffic on Allston Way en route to their next stop — UC Berkeley.
The protest prompted the brief closure of the downtown Berkeley BART station.
Saturday's protest comes about a month after a rioting crowd forced UC Berkeley officials to cancel a speech by controversial alt-right speaker, Milo Yiannopoulos.
NBC Bay Area's Christie Smith and the Associated Press contributed to this report.