A woman protesting over the police killing of an unarmed black man has been struck by the car of a sheriff's deputy.

Video filmed by a bystander showed the vehicle edging along the road before hitting the protester at a vigil for Stephon Clark, who was shot dead last month in his grandparents’ backyard in Sacramento, California.

The woman was taken to hospital with minor injuries.

Sacramento County Sheriff’s Office said it had launched an internal review of the collision, which is also under investigation by the California Highway Patrol.

The sheriff’s office said protesters had been “yelling while pounding and kicking the vehicles’ exterior”.

“The collision occurred while the patrol vehicle was traveling at slow speeds,” said spokesman Sgt Shaun Hampton. He said the deputy's vehicle had scratches, dents and a shattered rear window following the collision - which he blamed on "vandals" in the crowd.

The injured woman was identified by the Sacramento Bee as 61-year-old Wanda Cleveland.

"He never even stopped," she told the newspaper. “It was a hit-and-run. If I did that I’d be charged.”

About 150 people were at the vigil on Saturday night. Crowds held signs saying “Stop Police Rage” and “Power to the People” during the latest rally in a fortnight of growing anger over Clark’s death.

The 22-year-old father-of-two was shot six times in the back by two Sacramento police officers on on 18 March. The officers said that they believed the man was armed, although all that was found at the scene was a mobile phone.