BERKELEY, Calif. (KTVU) - At its peak, about 2,000 people packed into Martin Luther King Jr Civic Center Park and the surrounding area.
A event called No to Marxism Rally was originally scheduled but the city of Berkeley denied a permit for it and the organizer asked supporters not to show up.
But counter protestors and Trump supporters still showed up at the park. The latter was vastly outnumbered.
Both sides talked over each other while neither side listened.
Counter protestors shouted, "Go home Nazi's."
They accused Trump supporters of being racist.
Incident after incident, police moved Trump supporters away from the counter protestors when the exchanges became heated to keep them from turning violent.
Police say one person who was removed by officers for his own safety was Joey Gibson.
He's the head of Patriot Prayer who organized Saturday's protest at Crissy Field in San Francisco and cancelled it.
Others were also escorted out of the park by police.
"The police were forced to drag us over here. They want us to walk back to our car when people have just threatened us. We're going to get you. We're going to get you because they think we're white supremacists no matter how much we say we're against white supremacy," says Johnny Benitez.
He describes himself as being part of the "America First" movement. He tells KTVU he came from Orange County to support the No to Marxist Rally, but that he and his companion Irma Hinojosa were forced out of the park by counter protestors.
"People in masks surrounded us and tried to drag us away," says Hinojosa.
"The fact that we have to leave this way is a shame," says Benitez.
Other Trump supporters say they came to the park even though the original protest was cancelled because they wanted a space to express their opinions.
"If people threaten rallies, no matter what side they're on, they're just bullying them not to have rallies anymore, especially when those rallies are just about free speech," says David Feiner, a Trump supporter who says he's from Southern California.
KTVU crews saw numerous people with their hands zip tied and taken away by police.
Initially, people wearing a mask or carrying any object that could be used as a weapon were banned from the park.
Some counter protestors set off purple smoke bombs possibly as a diversion to police.
Soon after, a large group dressed in black, with their faces covered, often the trademark of Antifa, short for Anti-Fascists leftists, rushed into the park by scaling barricades.
They released water from the barricades so they could move them out of the way.
"I don't support silencing people and their opinions. Like right now, there's people throwing stuff at cops .I don't support that. These are people defending our city," says Abraham Youhana, a UC Berkeley student.
When the group dressed in black marched out of the park, police used a smoke grenade to disperse the crowd.
Things started winding down around 3pm.
Police tell KTVU 13 people were arrested.
Most were for bringing into the park items that were prohibited.
Police say six people suffered non-life threatening injuries.