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.
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.
Police in Washington DC have fired tear gas at demonstrators who set fire to properties near the White House. They include a historic church, St John’s Episcopal Church, known as the church of the presidents, near the White House.
It has emerged that in Friday night’s unrest, President Donald Trump was briefly taken by the secret service into an underground bunker at the White House, for his safety.