Washington, D.C., Mayor Muriel Bowser (D) announced a 7 p.m. curfew on Monday night following an outbreak of violent demonstrations across the nation’s capital and dozens of cities across the U.S.

Bowser said “significant damage” had been done to the downtown areas, as protests over the death of George Floyd after his arrest by Minneapolis police turned violent, with incidents of arson, vandalism and clashes between protesters and the police.

“Every American should be outraged by the murder of George Floyd,” Bowser said. “I want to implore D.C. residents to think of ways to be part of the solution, not part of the destruction.”

Washington Police Chief Peter Newsham said 88 people were arrested on Sunday night, with half of those charged with “felony rioting.” Seven police officers were injured but none were hospitalized.

Newsham said the antagonists appeared to be “organized in nature” and that the police will make further arrests after analyzing camera footage.

The police chief declined to elaborate on what organization might be behind it, saying only that “they were largely from this region.” The city is offering $1,000 rewards for information that leads to arrests of suspected criminals.

The Monday night curfew will begin at 7 p.m. and extend until morning. It will not impact journalists covering protests or other “essential employees.”

“People are torn because they feel so sad and angry about the killing of George Floyd, but also they don’t want their city torn up, so that’s what we’re managing,” Bowser said.

The nation is undergoing one of the most intense periods of civil unrest in modern times, as anger at law enforcement over the death of Floyd, an unarmed black man, boils over.

Minneapolis policeman Derek Chauvin has been arrested for Floyd’s death after video emerged showing him restraining Floyd by kneeling on his neck. Floyd died on the scene.

Broadcast and cable news outlets have been beaming in disturbing video of police aggressively clashing with protesters, vandalism and stores and businesses being ransacked in major cities across the country.

In D.C., several landmarks were vandalized, including the Lincoln Memorial, the World War II Memorial and a statue of Brigadier General Casimir Pulaski. St. John’s Church, where scores of past presidents have attended services, was set on fire.

President Trump briefly retreated to an underground bunker on Friday night as the protests swelled around the White House.

The president spent much of the weekend angrily tweeting about what he described as left-wing “anarchists” being allowed to run rampant due to Democratic politicians failing to enforce law and order in their cities.

Democrats have fired back at the president, accusing him of fanning racial tensions by threatening violence against the protesters or using loaded terms about releasing “vicious dogs” on those seeking justice for Floyd.

“That type of language needs to stay in the past,” Bowser said Monday. “I think that the president has a special role to make sure that people know that justice will be served, and that’s his primary role now.”

The protests also come as much of the nation remains on lockdown due to the global coronavirus pandemic, which has claimed the lives of more than 100,000 Americans.

Bowser and Dr. LaQuandra Nesbitt, the director of the District of Columbia Department of Health, said they worried that mass gatherings downtown might hasten the spread of the virus, even if many of the protesters were wearing facial coverings.

“They are wearing masks but they are still gathering in large numbers. … They are not social distancing, and face coverings are not a replacement for individuals who are not social distancing,” Nesbitt said. “Those are a concern from a public health perspective.”