Demonstrations began on Saturday after Sylville Smith (23) was shot and killed during foot chase
Unrest has continued overnight in the US city of Milwaukee after a police officer shot and killed a black man.
There were reports of shots being fired as demonstrators took to the streets for a second night in protest at the killing.
The Milwaukee Police Department said one officer had to be taken to hospital after a rock was thrown through the windshield of a squad car.
Debris was also hurled at officers at they worked to disperse what police described as “small, disorderly” groups.
“Multiple arrests" were also said to have been made in the Sherman and Burleigh areas.
It came a day after rioters hurled rocks and set buildings alight during the first night of violent clashes.
Demonstrations began on Saturday after 23-year-old Sylville Smith was shot and killed during a foot chase.
Police said he had been ordered to drop a handgun but had failed to do so.
Wisconsin Governor Scott Walker yesterday made the National Guard available to support Milwaukee police in the event of further violence.
The shooting happened in one of the city's poorest areas, where the community is predominantly black.
The unrest is the latest in a series of disturbances to hit US cities, including Baton Rouge, Dallas, and Ferguson, Missouri, following fatal police shootings.
All of the previous incidents involved young black men, giving rise to the Black Lives Matter movement.