National Guard troops were visible late Wednesday but their numbers reduced as well from the night before, when a squad car was torched by protesters angered by a grand jury's decision not to indict the white police officer who fired the shots that killed Michael Brown, 18, in August.
Police arrested several people at a demonstration in nearby St. Louis earlier Wednesday.
St. Louis County police said they were looking for an AR-15 rifle stolen from a squad car that was set on fire during the first night of violent protests Monday in Ferguson.
"Rioters yanked out the high-powered police rifle and the rack in which it was stored," Sgt. Brian Schellman told KDSK-TV.
Members of a group calling itself Reverend Billy and the Stop Shopping Choir, a radical performance group from New York, serenaded National Guard troops protecting the police station. Billy Talen, who leads the group, called on Americans to take part in "blackout Black Friday" and boycott major retailers on this traditionally busy shopping weekend to show solidarity with Ferguson protesters.
"You have a racist killing police department," Talen said. "It goes with how society spends in its everyday life."
