While the "No Kings" protest remained peaceful for the majority of the day, law enforcement arrested 38 demonstrators, mainly for violating the downtown curfew Saturday night. 

Out of the more than three dozen people arrested, 35 violated curfew, one failed to disperse, one resisted arrest and one resisted, obstructed or delayed an officer, according to the Los Angeles Police Department. 

LAPD has arrested 561 people since June 7, after ICE protesters began to clash with law enforcement in downtown L.A. In the last week, 12 officers have suffered injuries during the demonstrations in the city. 

The nationwide "No Kings Day of Defiance" protests focused on countering the military parade held in honor of the U.S. Army's 250th anniversary, which also coincided with President Trump's birthday. The event's organizers said 5 million people participated in demonstrations in more than 2,100 cities across the country. 

While they were planned before the ICE protests in L.A., many used the opportunity to denounce the immigration operations happening in Southern California. 

The gathering downtown was scheduled for 9:45 a.m. to 1:30 p.m., but many activists stayed well into the afternoon. 

"Today, over 200,000 people gathered peacefully in downtown Los Angeles to protest the egregious overreach of this administration," No Kings spokesperson Hunter Dunn said in an email. "While the official No Kings event concluded earlier in the day, many remained in the streets to continue their nonviolent dissent."

While the demonstration remained peaceful throughout the day, law enforcement ordered protesters to leave the area after "people in the crowd are throwing rocks, bricks, bottles and other objects," when the march passed by the  at around 3:50 p.m., according to LAPD. 

Protesters interviewed by CBS News Los Angeles blamed the escalation on the police. 

"They came in super, super hard and aggressive, and that's what created all of this," one protester said. "No warning. They just masked up ... It's upsetting because how are people supposed to feel like their voices are being heard when they're being violently put down by the state itself."

Police and L.A. County Sheriff's deputies deployed smoke and flash-bangs while moving the crowd away from the federal building. Aerial footage shows officers detaining several people.

"The only time our deputy sheriffs are utilizing that less-lethal weapon is when they are being attacked or others are being attacked," L.A. County Sheriff Robert Luna said Saturday night. "They're not just using it indiscriminately. Sometimes the videos don't show it, but sometimes you have individuals launching the craziest things at them, from pyrotechnics to Molotov cocktails."

A video from inside L.A. City Hall showed the crowd throwing canisters of tear gas back at law enforcement. 

"I look at today and I'm very disappointed," L.A. Police Chief Jim McDonnell said Saturday night. "We started out with a very peaceful protest earlier in the day. About mid-afternoon or so, then it got violent when you had the agitators in the group start assaulting officers with missiles, rocks, bottles, fireworks, and they had a high-ground position on the officers."