Governors in several US states have called in National Guard troops as protests over police killings of black men intensifies.
Similar scenes of unrest unfolded across several cities on Saturday from New York to Tulsa to Los Angeles, where police fired rubber bullets to scatter crowds and at least one police car burned.
The protests - which began in Minneapolis following Monday's death of George Floyd during an arrest - have left parts of that city a grid of broken windows, burned-out buildings and ransacked stores.
In Washington, President Donald Trump sent tweets ridiculing protesters outside the White House who were among thousands nationwide incited by the death of Floyd, who died after a policeman pressed his knee onto his neck for more than eight minutes.
The demonstrations have become a national phenomenon, with protesters decrying years of deaths at police hands.
In Tulsa, Oklahoma's Greenwood District, the site of a 1921 massacre of black people that left some 300 dead, protesters blocked intersections and chanted the name of Terence Crutcher, a black man killed by a police officer in 2016.
Other peaceful protests were being held in California, Delaware, Florida, Massachusetts, New Jersey, Pennsylvania and South Carolina.
In Tulsa and Wilmington, Delaware, demonstrators made their way onto nearby interstates and shut them down temporarily.
In Tallahassee, Florida, a pickup truck drove through a crowd of protesters, sending some running and screaming as the vehicle stopped and started and at one point had a person on its hood, police said. No serious injuries were reported.
In Columbia, South Carolina, a television reporter for WIS-TV was injured by rocks thrown amid protests outside the Columbia Police Department.
Several hundred people participated in the demonstration, tearing down the American and state flags in front of the police department's headquarters. They also swarmed a Columbia police car, breaking its windows, The State reported.
In Los Angeles protesters chanted "Black Lives Matter," some close to the face shields of officers.
Police used batons to move protesters back and shot rubber bullets to scatter the crowd. One man used a skateboard to attempt to break the windshield of a police SUV. A spray painted police car burned in the streets.
Los Angeles mayor Eric Garcetti imposed an overnight curfew in a bid to reduce looting, property damage and violence.
Meanwhile, Trump fired off a series of tweets taunting protesters and praising the Secret Service, who used shields and pepper spray to push back people gathered to protest Floyd's death and the president's response.
Trump tweeted he had watched from inside the White House as officers "let the 'protesters' scream & rant as much as they wanted, but whenever someone .... got too frisky or out of line, they would quickly come down on them, hard - didn't know what hit them".
Trump said if the protesters had managed to breach the White House fence, "they would ... have been greeted with the most vicious dogs, and most ominous weapons, I have ever seen".
The US president ended the last of five tweets by saying, "Tonight, I understand, is MAGA NIGHT AT THE WHITE HOUSE???"
Minnesota Governor Tim Walz fully mobilised the state's National Guard and promised a massive show of force to help quell unrest that has grown increasingly destructive.
"The situation in Minneapolis is no longer in any way about the murder of George Floyd," Walz said. "It is about attacking civil society, instilling fear and disrupting our great cities."
The Pentagon has ordered the US army to put military police units on alert to head to the city on short notice, at Trump's request, insiders said.
The rare step came as the violence spread to other cities, with a man shot dead in Detroit, police cars attacked in Atlanta and skirmishes with officers in New York City.
Criminal charges were filed on Friday against the white police officer who held his knee on the neck of Floyd, a black man who was handcuffed at the time. However, this has done nothing to stem the widespread anger.
Derek Chauvin, 44, has been charged with third-degree murder and second-degree manslaughter.
Chauvin was also accused of ignoring another officer who expressed concerns about Mr Floyd as he pleaded that he could not breathe, while Chauvin pressed his knee into his neck for several minutes.
Floyd had been arrested on suspicion of using a counterfeit twenty dollar note at a store.
Chauvin, who was fired along with three other officers who were at the scene, faces more than 12 years in prison if convicted of murder.
After a tumultuous Friday night, racially diverse crowds took to the streets again for mostly peaceful protests in dozens of cities on Saturday. The previous day's protests had also started calmly before many descended into violence.
The massive crowds involved, with many people not wearing masks or practising social distancing, raised concerns among health experts about the potential for the spread of the coronavirus.
Hundreds of people were arrested on Friday, and police used batons, rubber bullets and pepper spray to push back crowds in some cities.
Many departments reported officers were injured, while social media was awash in images of police using forceful tactics, throwing protesters to the ground, using bicycles as shields, and trampling a protester while on horseback.
Australian Associated Press