Around 400 people were arrested as anger over the killing of George Floyd erupted into violence across Los Angeles Saturday, prompting a citywide curfew and deployment of the National Guard.

It was the fourth and most fervent day of protesting in the city, marked by tense standoffs as skirmish lines formed between law enforcement and demonstrators, largely in the Fairfax District and downtown. Police cars burned, protesters were hit with rubber bullets, and businesses were emptied of merchandise.

The two groups disagree on whose side was first to spark the violence.

Patrisse Cullors, a cofounder of the L.A. chapter for Black Lives Matter, said she was with a group that had been demonstrating peacefully for two hours when police began deploying less-lethal force.

“It was honestly one of the most beautiful and moving protests that I’ve been to in the last seven years that we’ve been protesting the death of black people,” she said Sunday. “And the minute we stopped our protests, the police came out and started shooting rubber bullets and gassing people.”

A woman who demonstrated in Beverly Grove Saturday told the Los Angeles Times her group was also fired upon as they stood chanting. “How are you going to hit people with rubber bullets?” she asked.

Cullors said she spoke with organizers across the nation, many of whom witnesses similar escalations against peaceful protesters. It makes her “deeply concerned” about the presence of the National Guard, which Mayor Eric Garcetti says will remain in the city indefinitely.

“This idea that police brutality and police terror has ended in Los Angeles or any other cities is a false idea, and it’s unfortunate because many of our elected officials are not holding law enforcement accountable,” she said. “So we just keep going through the same cycle.”

LAPD Chief Michel Moore described his department’s response to this weekend’s protests as the challenge of a lifetime.

Officers were hit with projectiles, including glass bottles and rocks, leaving five of them injured. Two were hospitalized, including one whose skull was fractured by a brick, according to Moore. Others suffered contusions and broken bones.

The chief said some protesters were also hurt by projectiles. LAPD did not release information on the number of protesters injured.

Moore said his officers don’t interfere until after they determine a situation is unsafe and have ordered protesters to disperse.

“We have the authority and the responsibility to close that area, and the participant has a responsibility to leave,” he said. “When that does not happen, we take action to restore order.”

Moore said officers’ restraint exceeded expectations, although he also personally witnessed times force crossed the line. And Moore said he stepped in himself to negotiate at the front of skirmish lines, even though the protesters don’t have authority.

Some demonstrators argue that law enforcement doesn’t get to choose how police brutality is protested.

Alexis Equihua, a 20-year-old who watched as a Melrose Avenue shop was looted Saturday, told the L.A. Times violence may be necessary.

“Sometimes peaceful is not enough,” she said. “I’m not one of the people vandalizing, but honestly, I get it. They feel like actions speak louder than words.”

Demonstrators were taken into custody on suspicion of burglary, looting, vandalism, failure to disperse and violating curfew, and at least one person was accused of being a felon in possession of a gun, the L.A. Police Department said in a news release Sunday.

A total of 11 officers have been hurt since the unrest boiled over in L.A. Friday. That night, hours of marching downtown was declared an unlawful assembly after some began looting, drawing graffiti on police cars and setting off fireworks in the street. About 500 people were arrested.

LAPD says it’s still working to assess the full extent of this weekend’s damage. Rallies are expected to continue Sunday night, despite a countywide curfew from 6 p.m. until 6 a.m. Monday.

Cullors drew a contrast between this weekend’s events and the law enforcement response to anti-lockdown demonstrators like the armed group that stormed the Michigan State Capitol.

“We don’t understand how we can gather peacefully and then end up in a situation where police are violating our rights,” she said. “I think that’s the question that we need to be offering right now: Who’s able to assemble peacefully, and then who gets who gets the worst end of the stick when it comes to law enforcement?”

Cullors said Black Lives Matter L.A. is seeking police accountability and reprioritization of public spending in L.A. city and county, so that less is given to law enforcement and more to communities. The group plans to continue protesting.

Moore said his department will use the same tactics going forward, starting by trying to arrest those engaging in violence after ordered to disperse. And he promised to investigate every complaint of misconduct or excessive force.