A white off-duty St. Louis city policeman shot and killed a black teenager who fired on him on Wednesday, police said, triggering protests just miles from the flashpoint suburb of Ferguson.
Ferguson has been racked by near nightly protests since the fatal shooting in August of black 18-year-old Michael Brown by a white police officer.
In Wednesday's incident another officer, a 32-year-old working for a security company, fired 17 times at another 18-year-old, who had himself fired at least three shots, St. Louis Metropolitan Police Chief Sam Dotson said.
The dead man was one of three people who fled after being approached and then chased by the officer, a six-year veteran of the department who was wearing his city police uniform, Dotson told a news conference.
A crowd of around 200 gathered at the scene in south St. Louis. Many of the protesters marched to a major thoroughfare, partially blocking traffic and chanting "Whose streets? Our streets?" as a police helicopter hovered overhead.
At one point, roughly a dozen people punched and kicked two occupied police vehicles, one that was marked and another that was unmarked. Demonstrators then broke the back window of a marked police vehicle.
As of early Thursday morning, none of the protesters had been arrested, Dotson said.
'MICHAEL BROWN ALL OVER AGAIN'
Teyonna Myers, 23, told the St. Louis Post-Dispatch newspaper that she was the cousin of the suspect and that he was unarmed when he was killed. Police have not named the suspect.
"He had a sandwich in his hand, and they thought it was a gun. It's like Michael Brown all over again," she told the paper.
The officer was not hurt and a gun was recovered from the scene, police said.
The officer has been placed on administrative leave and an investigation was under way, police said.
The shooting occurred in the neighborhood of Shaw, a historic district with low levels of crime. As of September, there had been no homicides this year and five cases of aggravated assault, according to police crime statistics.