More than 50 people have staged a protest outside a Detroit area police department to demand the sacking of two white officers involved in the arrest of a black man who was pulled from his car and punched in the head several times.
The demonstration in Inkster came after video of the bloody arrest of 57-year-old Floyd Dent in January was aired by TV station WDIV on Tuesday.
Inkster police chief Vicki Yost met protesters and said the incident is being investigated by Michigan state police. She said the officers involved are on paid leave.
Civil rights leader the Rev Charles Williams II has threatened to "shut Inkster down until we get justice".
Police treatment of black men has become a major issue in the US in the aftermath of killings in Ferguson, Missouri, and in New York City.