Violence has erupted in cities across the US on the sixth night of protests sparked by the death in police custody of African-American George Floyd, reports BBC.
Curfews have been imposed in nearly 40 cities, but people have largely ignored them, leading to tense stand-offs.
Riot police clashed with protesters in New York, Chicago, Philadelphia and Los Angeles, firing tear gas and pepper bullets to try to disperse the crowds.
Police vehicles were set on fire and shops were looted in several cities.
The National Guard - the US reserve military force for domestic emergencies - said on Sunday that 5,000 of its personnel had been activated in 15 states and Washington, DC, where crowds once again gathered near the White House, this time lighting fires and throwing stones at riot officers.
"State and local law enforcement agencies remain responsible for security," the National Guard added.
What's the latest on the protests?
There were multiple instances of police vehicles being vandalised and set alight on Sunday. Riot officers continued to respond with tear gas and flash grenades.
In Philadelphia, local TV stations showed people smashing police cars and looting at least one store.
US President Donald Trump tweeted: "Law & Order in Philadelphia, NOW! They are looting stores. Call in our great National Guard".
Looting was also reported in Santa Monica, California.
In Minneapolis, where Mr Floyd lost his life, a lorry driver was arrested after reportedly breaching a road barrier before speeding towards a crowd of protesters marching along a major highway.
Footage posted on social media showed dozens of people surrounding the vehicle and pulling the driver out from behind the wheel after it came to a stop.
The driver was later taken to hospital with minor injuries. There were no immediate reports of other casualties.
Minnesota's Governor Tim Walz said the motive of the driver was unclear, adding: "To not have tragedy and many deaths is simply an amazing thing."
In Denver, thousands of people protested peacefully in Colorado State Capitol by lying face down with their hands behind their backs and chanting: "I can't breathe."
Large-scale protests also took place in Atlanta, Boston, Miami and Oklahoma City.
There were also several reported incidents of riot police responding disproportionately to the demonstrators. In Atlanta, Georgia, two officers were sacked on Sunday for using excessive force - including firing a taser - on two young college students.
The Floyd case has reignited US anger over police killings of black Americans. For many, the outrage also reflects years of frustration over socio-economic inequality and segregation, not least in Minneapolis itself.
Hundreds of people have been arrested since the protests began a week ago.
A white ex-policeman has been charged with murdering Mr Floyd, 46, in Minneapolis.
Derek Chauvin, 44, is due to appear in court later on Monday.
It follows the high-profile cases of Michael Brown in Ferguson, Eric Garner in New York and others that have driven the Black Lives Matter movement.
What happened to George Floyd?
On the evening of Monday 25 May, police received a phone call from a neighbourhood grocery store alleging that George Floyd had paid with a counterfeit $20 note.
Officers were attempting to put him in a police vehicle when he dropped to the ground, telling them he was claustrophobic.
According to police, he physically resisted officers and was handcuffed. Video of the incident does not show how the confrontation started.
With Mr Chauvin's knee on his neck, Mr Floyd can be heard saying "please, I can't breathe" and "don't kill me".
According to a preliminary autopsy by the county medical examiner, the police officer had his knee on Mr Floyd's neck for eight minutes and 46 seconds - almost three minutes of which was after Mr Floyd became non-responsive.
Nearly two minutes before Mr Chauvin removed his knee the other officers checked Mr Floyd's right wrist for a pulse and were unable to find one. He was taken to hospital and pronounced dead around an hour later.