Angry crowds confronted the police in Milwaukee on Saturday night, setting fires and throwing rocks, after an officer shot and killed a fleeing armed man earlier in the day.
One fire, at a gas station in the Sherman Park neighborhood, burned unattended while gunshots kept firefighters from extinguishing it. Other fires burned at an auto-parts store, a beauty supply company and a bank branch.
One police officer was hospitalized with a head injury after a brick was thrown through the window of his patrol car, Mayor Tom Barrett said at a news conference early Sunday morning.
The police made three arrests on unspecified charges during the mayhem, during which crowds of at least 200 people flooded the streets, said Assistant Chief James Harpole of the Milwaukee police.
The violence erupted after an officer killed a man who the police said was armed with a semiautomatic handgun and who fled after a traffic stop.