Several people protesting against a grand jury decision not to indict a police officer over the fatal shooting of an unarmed black 18-year-old stormed into City Hall in St Louis, leading police to lock down the building and call in more than a hundred additional officers.
Those who made it inside City Hall were part of a group of about 200 protesters who marched and held a mock trial of Darren Wilson, the white police officer who shot and killed Michael Brown during a confrontation in Ferguson, a St Louis suburb.
At least two people were arrested after the City Hall incident, in which the protesters shouted "Shame, shame" while rushing into the building.
The racially charged case has stoked passions nationwide, triggering debates over the relations between black communities and law enforcement. Since the grand jury's decision was announced on Monday night, protesters in cities throughout the country have rallied behind the refrain "hands up, don't shoot," and drawn attention to other police killings.
As the tension in Ferguson eased somewhat, Mr Wilson broke his long public silence, insisting on national television that he could not have done anything differently in the August 9 confrontation. He testified during the grand jury hearings that he felt threatened and that Mr Brown tried to grab his gun, something the Brown family has said they do not believe.
An influx of National Guardsmen helped make the second night of protests in Ferguson much calmer than the first, when 12 commercial buildings were burned down and several others were set ablaze.
Demonstrators took to the streets again last night, but there were hundreds of additional troops standing watch over neighbourhoods and businesses. Officers still used some tear gas and pepper spray, and demonstrators set a squad car on fire and broke windows at Ferguson's City Hall.
Missouri Governor Jay Nixon sent a large contingent of extra National Guardsmen, reserve troops that state governors can call up during emergencies. The governor ordered the initial force of 700 to be increased to 2,200.
Guard units protected the Ferguson Police Department and left crowd control, arrests and use of tear gas to local officers. In one commercial area this morning, a soldier was stationed at every few store fronts, and some were on rooftops.
There were 58 arrests overnight in Ferguson and St. Louis.
Large demonstrations were held throughout the country for a second day. Some were peaceful, such as in New York and Seattle, where high school students walked out of classes.
Other events were not as calm. In Oakland, California, a crowd of protesters smashed windows at a car dealership, restaurants and convenience stores.
A rally that drew thousands in Minneapolis took a turn when a car struck a protester and drove through a pack of others. And in Portland, Oregon, police used pepper spray and made arrests after about 300 people disrupted bus and light rail traffic by walking across a bridge.
During an interview with ABC News, Mr Wilson said he has a clean conscience because "I know I did my job right".
Mr Wilson, 28, had been with the Ferguson police force for less than three years before the shooting. He told ABC that Mr Brown's shooting was the first time he fired his gun on the job.
Asked whether the encounter would have unfolded the same way if Mr Brown had been white, Mr Wilson said yes.
The grand jury's decision means Mr Wilson will not face state charges.
Attorneys for the Brown family said the grand jury process was rigged from the start to clear Mr Wilson. One of them, Anthony Gray suggested that prosecutor Bob McCulloch presented certain testimony to discredit the process, including from witnesses who did not see the shooting.
The attorneys vowed to pursue federal charges. The US Justice Department is conducting a civil rights investigation into the shooting, but federal investigations of police misconduct face a steep legal standard to justify a prosecution.
Mr Brown's parents made public calls for peace in the run-up to Monday's announcement, and on Tuesday, their representatives again stressed that the people setting fires were not on Michael Brown's side.
Videos that were widely circulated showed Mr Brown's mother, Lesley McSpadden, standing atop a car and breaking down as the announcement of the grand jury decision blares over the stereo.
Her husband, Mr Brown's stepfather, comforts her, then begins angrily yelling "Burn this bitch down!" to a crowd gathered around him. Asked about the comment at a news conference, family attorney Benjamin Crump said the reaction was, "raw emotion. Not appropriate at all. Completely inappropriate."