Gunshots rang out and police lobbed tear gas at an angry crowd that threw bottles outside the Ferguson Police Department in suburban St. Louis after a grand jury decided not to indict a white officer in the shooting death of an unarmed black teen.
Outrage over the decision fueled what had been mostly peaceful protests across the United States on Monday, including in New York City where marchers chanting "Black lives matter" snarled traffic on Broadway through Times Square.
In Chicago, demonstrators walked up Lake Shore Drive carrying banners that read "Justice for Mike Brown" - the 18-year-old who was shot and killed in Ferguson on Aug. 9.
Police in Ferguson used smoke canisters and trucks to force waves of violent protesters down the street away from the police building soon after sporadic gunshots were heard. Flames from a burning car rose into the night sky.
Whistles pierced the air as some of the hundreds of protesters tried to keep the peace, shouting, "Don't run, don't run."
Police who formed a wall of clear riot shields outside the precinct were pelted with bottles and cans as the crowd surged up and down the street immediately after authorities said the grand jury had voted not to indict Officer Darren Wilson.
"Murderers, you're nothing but murderers," protesters in the crowd shouted. One woman, speaking through a megaphone said, "Stinking murderers."
Dozens of police and military vehicles were poised for possible mass arrests not far from the stretch of Ferguson streets that saw the worst of the rioting after Wilson shot Brown in August.
"They need to feel the pain these mothers feel at the (expletive) cemetery," shouted Paulette Wilkes, 40, a teacher's assistant who was in the crowd at the police department.
A smaller, calmer crowd of about three dozen protesters gathered outside the courthouse where the grand jury had met. In that crowd, a white woman held a sign that read: "Black Lives Matter." Many of the protesters looked stunned.
"That's just how the justice system works - the rich are up there and the poor are down here," said Antonio Burns, 25, who is black and lives in the Ferguson area. The police "think they can get away with it," Burns said.
A handful of Amnesty International volunteers in bright vests tried to maintain the peace. Brown's family quickly urged a non-violent response to the grand jury's decision.
Officials urged tolerance and assured residents that the National Guard would provide security at critical facilities like fire houses, police stations and utility substations.
"I do not want people in this community to think they have to barricade their doors and take up arms," St. Louis County Executive Director Charlie Dooley said before the grand jury's decision was announced.
