About 40 people were arrested just north of Minneapolis in a second night of unrest over the police shooting of black man Daunte Wright.
Protesters in the city of Brooklyn Center defied a curfew and threw objects at police, who responded with flash grenades and tear gas.
The police chief said the 20-year-old was shot and died after an officer mistook her gun for a Taser. The shooting came as the high-profile George Floyd murder trial continues in a courtroom just a few miles away.