A dozen cities across the United States have experienced protests overnight over the decision not to charge a white policeman who killed an unarmed black teenager in Ferguson, Missouri.
Demonstrations from New York to Seattle were largely peaceful but rioting broke out in Oakland, California.
There was some unrest in Ferguson itself, with police making 44 arrests, but the suburb of St Louis did not see destruction on the scale of the previous night, the BBC reported.
The officer who killed Michael Brown there says he has a "clean conscience".
Darren Wilson, who shot the 18-year-old on 9 August, told ABC News that in the struggle which preceded the shooting, he had felt "like a five-year-old holding on to [US wrestler] Hulk Hogan".
Many in Ferguson's predominantly African-American community had called for the officer to be charged with murder, but the grand jury's decision means the police officer will not face state criminal charges over the shooting.
Lawyers for Mr Brown's family denounced the grand jury's decision, saying they "strongly objected" to the way prosecutor Bob McCullough laid out the case, while condemning the violence that followed.
St Louis County police chief Jon Belmar said last night had been "generally a much better night" in Ferguson, a town of 21,000 people.
Tear gas was fired just once, he said, when rioters smashed windows at the Ferguson town hall. There was only one report of shooting, he added, when a car was set alight.
More than 2000 National Guard soldiers were deployed to assist police in keeping order in and around Ferguson.
Protests were reported in 13 cities: St Louis itself as well as Philadelphia, Seattle, Albuquerque, New York, Cleveland, Los Angeles, Oakland, Minneapolis, Atlanta, Portland, Chicago and Boston.
'Hands up, don't shoot'
Demonstrators across the US chanted the refrain "hands up, don't shoot" in reference to some witness statements that said Mr Brown was raising his hands in surrender when he was killed.
But many protests also referred to police killings in their own city, including a man in New York who died after being placed in a "chokehold" by a police officer.
In Oakland, in the San Francisco Bay area, rioters vandalised police cars and attacked businesses in the centre during a second night of unrest in the port city of 406,000 people.
Long-standing grievances about Oakland's police department are believed in part to be fuelling the protests there, the BBC reported.
In other incidents:
- Protesters briefly stopped traffic in central Los Angeles before police moved in to clear them off.
- Hundreds blocked traffic in Cleveland, Ohio, in a separate demonstration over the fatal shooting of a 12-year-old boy by a police officer.
- A car ploughed into protesters blocking a road at a rally in Minneapolis, injuring one person.