Police in St Louis use tear gas to disperse protesters after the fatal shooting of a black teenager, who officers say pointed a gun at them.
The shooting took place on Wednesday as St Louis officers carried out a search warrant. Two young men were seen running out of the back of the house, and the police ordered them to stop in an alley behind the house.
One suspect pointed a gun at the officers, St Louis Police Chief Sam Dotson said, and officers fired four shots in response, killing him.
“Detectives were looking for guns, looking for violent felons, looking for people that have been committing crimes in the neighbourhood,” Mr Dotson said.
Police identified the dead man as Mansur Ball-Bey, 18. The second youth fled. They said Ball-Bey’s gun was one of three stolen firearms recovered from the scene, as well as a quantity of crack cocaine.
St. Louis police said the officers involved in the shooting were white, aged 33 and 29, each with about seven years on the force. They are on administrative leave.
The incident took place near Ferguson which has seen widespread protest following the shooting of unarmed black teenager Michael Brown a year ago.
Crowds gathered at a nearby road intersection not long after the shooting, and then later in the evening.
Mr Dotson said some protesters threw bricks and glass bottles at officers, who used shields to protect themselves and then tear gas to disperse the crowd.
A car was set on fire and some local businesses had reported robbery attempts, he said.Fire services were also called out after a vacant building was set ablaze.
Nine people were arrested on charges of impeding traffic and resisting arrest, police said.