Fires burned near the White House, stores were looted in New York City and southern California, and a tanker truck drove into marchers in Minneapolis as the United States struggled to contain chaotic protests over race and policing.
The unrest began with peaceful protests over the death of a black man, George Floyd, in police custody, last Monday.
In Washington, D.C., protesters set fires near the White House on Sunday. The smoke mixed with billowing clouds of tear gas as police sought to clear from the area crowds chanting “George Floyd”.
Sporadic violence broke out in Boston following peaceful protests as activists threw bottles at police officers and set a cruiser on fire. Philadelphia announced a 6 p.m. to 6 a.m. curfew.
On the West Coast, there were clashes in Portland, Oregon, where TV footage showed small fires burning as police fired tear gas at protesters who set off fireworks.
The demonstrations brought out a diversity of people.
Thousands of people gathered peacefully on Sunday afternoon for a rally in St. Paul, adjacent to Minneapolis, as state troopers surrounded the state capitol building. About 170 stores in the city have been looted, its mayor told CNN.
Protests spread around the globe, with events in London and Berlin on Sunday and others on Monday, including in New Zealand, Australia and the Netherlands.
The eruptions of violence have not let up despite the arrest on Friday of former Minneapolis police officer, Derek Chauvin, 44. He has since been charged with third-degree murder.