Smoke is billowing from charred buildings after a night of rioting in Ferguson over a grand jury's decision not to indict the police officer who shot dead Michael Brown.
The Missouri town woke up to the damage caused overnight, estimated in the millions of dollars, as firefighters doused the blackened remains of a dozen buildings that were set ablaze.
Ferguson braced for another night of protests as anger continued to mount after white police officer Darren Wilson was cleared in the death of the black 18-year-old last August.
Monday night's protests were more destructive than any of the others in the immediate aftermath of the shooting, and they represented some of the worst racially charged riots in years.
Authorities reported hundreds of gunshots and looting as windows of police cars and stores were smashed and a group mobbed a police car.
As protesters hurled objects at officers, police fired tear gas and flash bang canisters at them.
More than 60 people were held in Ferguson and another 21 in St Louis, officials said, though no serious injuries were reported.
Protests also were staged in New York, Chicago, Seattle, Los Angeles, Oakland, California and Washington DC over the case - which has highlighted long-standing racial tensions across America.
Schools in Ferguson and surrounding areas said they planned not to open on Tuesday and city offices in Ferguson were also closed.
Protesters planned to demonstrate outside the courthouse in Clayton, Missouri, where the grand jury sat, as well as in the streets of Ferguson.
Officials vowed to deploy a stronger police presence in Ferguson.
Colin Jeffery of KTRS Radio in Missouri spoke to Newstalk Breakfast earlier, and he described the reaction of the Brown family to the verdict.
Obama appeals for calm from both sides
Jon Belmar, chief of the St Louis County police, said that unless his agency could bring in 10,000 officers, "I don't think we can prevent folks who really are intent on destroying a community."
The grand jury's decision means that Officer Wilson will not face any state criminal charges for killing Mr Brown.
Violence flared up moments after the decision was announced, and the situation quickly got worse.
Mr Brown's mother, Lesley McSpadden, sat atop a vehicle listening to a broadcast of the announcement. When she heard the decision, she burst into tears and began screaming before being whisked away by supporters.
Prosecuting Attorney Bob McCulloch said the jury of nine white people and three black people heard more than 70 hours of testimony from about 60 witnesses, including three medical examiners and experts on blood, toxicology and firearms.
After three months, it concluded that Officer Wilson, who testified that he feared for his life, had acted in self-defence.
Witnesses disagreed on whether Mr Brown's hands were up at the time he was shot, Mr McCulloch said, adding that Officer Wilson shot at the teen 12 times.
Lawyers for Mr Brown's family say he was trying to surrender when he was shot.
US President Barack Obama appealed for calm and understanding, pleading with both protesters and police to show restraint.
"We are a nation built on the rule of law, so we need to accept that this decision was the grand jury's to make," Mr Obama said.
