At least 12 officers have been injured during protests sparked by the police shooting of African-American Keith Lamont Scott in Charlotte, North Carolina.
Protesters destroyed marked police cars around the block of flats where the shooting took place, the Charlotte-Mecklenburg Police Department tweeted.
One officer was hit in the face with a rock, police said.
On September 20, Keith Lamont Scott, 43, was shot by a black officer and died in hospital.
Police say Keith Lamont Scott was carrying a gun and posed an “imminent deadly threat”, but relatives told local media he was not holding a weapon but a book.
Demonstrators outraged over the incident blocked streets and police used tear gas, local media reported.
Mayor Jennifer Roberts appealed for calm, and said the shooting of Keith Lamont Scott would be looked into.
“The community deserves answers and full investigation will ensue,” she tweeted.
“Will be reaching out to community leaders to work together.”
The unrest came a day after police in the city of Tulsa, in Oklahoma, said a black man they had killed on September 16 was unarmed.
Hundreds of people have been protesting outside police headquarters there.
Terence Crutcher was walking away with his hands in the air when he was shot by police, footage shows.
In Charlotte, officers had been looking for a different suspect at a block of flats when Keith Lamont Scott was killed, police spokesman Keith Trietley said.
They saw Keith Lamont Scott get out of a car carrying a gun before getting back in, he said. When the officers approached, Keith Lamont Scott got out of the car with the gun again and police opened fire after deeming him a threat.
Keith Lamont Scott was not the suspect police were originally looking for, Keith Trietley confirmed.
Brentley Vinson, the officer who shot Keith Lamont Scott, has been placed on administrative leave as part of police protocol.
A woman claiming to be Keith Lamont Scott’s daughter has contested the police department’s account in a Facebook video, the Charlotte Observer reports.
She says Keith Lamont Scott was unarmed and reading while he was waiting for his son’s school bus and was tasered before being shot four times.
She also said Keith Lamont Scott was disabled. Police have not responded to the claims but say they recovered a gun at the scene.