Fifteen people protesting against a decision not to indict the police officer who fatally shot 18-year-old Michael Brown have been arrested outside the Ferguson police department.
Tensions escalated overnight during an initially calm demonstration after police said protesters were illegally blocking West Florissant Avenue.
Missouri department of public safety spokesman Mike O'Connell told the St Louis Post-Dispatch 15 people were arrested.
The demonstration in Ferguson came after protesters earlier in the day temporarily shut down three large shopping malls in suburban St Louis.
Chicago, New York, Seattle and Northern California also saw demonstrations.
Mr O'Connell said charges would include peace disturbance and impeding the flow of traffic, and two people would be charged with resisting arrest and one with assault.
A group of about 100 protesters had marched down West Florissant Avenue to the city's police and fire departments chanting, blocking traffic and stopping in front of some businesses.
"I served my country. I spent four years in the Army, and I feel like that's not what I served my country for," said Ebonie Tyse, 26, of St Louis.
"I served my country for justice for everyone. Not because of what colour, what age, what gender or anything," she said.
Several stores lowered their security doors or locked entrances as at least 200 protesters sprawled onto the floor while chanting "Stop shopping and join the movement," at the Galleria mall in Richmond Heights a few miles south of Ferguson, Missouri, where Officer Darren Wilson fatally shot Mr Brown, who was unarmed, in August.
The action prompted authorities to close the mall for about an hour yesterday afternoon, while a similar protest of about 50 people had the same effect at West County Mall in nearby Des Peres. And several dozen demonstrators led to a temporary closure of the Chesterfield Mall.
Monday night's announcement that Mr Wilson, who is white, would not be indicted for fatally shooting black teenager Mr Brown, prompted violent protests that resulted in about a dozen buildings and some cars being burned. Dozens of people were arrested.
The rallies have been ongoing but have grown more peaceful this week, as protesters turn their attention to disrupting commerce, including on Black Friday yesterday.
In Oakland, more than a dozen people were arrested after about 125 protesters wearing T-shirts that read "Black Lives Matter" interrupted train services from Oakland to San Francisco, with some chaining themselves to trains.
Dozens of people in Seattle blocked streets, and police said some protesters also apparently chained doors shut at the nearby Pacific Place shopping centre.
In Chicago, about 200 people gathered near the city's popular Magnificent Mile shopping district, where Kristiana Colon, 28, called Friday "a day of awareness and engagement".
She is a member of the Let Us Breathe Collective, which has been taking supplies such as gas masks to protesters in Ferguson.
"We want them to think twice before spending that dollar today," she said of shoppers. "As long as black lives are put second to materialism, there will be no peace."
Missouri Governor Jay Nixon announced he will call a special session of the General Assembly to provide funding for public safety efforts related to protests.
His office said due to the increased presence of the State Highway Patrol and the Missouri National Guard in the region, the state's financial obligations for emergency duties are on track to exceed what had been appropriated.