Authorities in Minnesota said at least five police officers were injured in a protest sparked by the recent police killings of black men in Minnesota and Louisiana on Saturday night.
St. Paul police said the officers were injured after some protesters threw rocks, firecrackers and other debris at them.
The Minneapolis Star-Tribune reported that many arrests were made.
According to Fox 9, protesters also hurled bricks, glad bottles, construction rebar and liquids at the officers. A Molotov cocktail was also thrown toward the officers.