Another black teenager has been shot dead by an off-duty police officer in St Louis, Missouri, leading to angry demonstrations on the streets.
The white officer was on patrol for a private security company when he exchanged fire with an 18-year-old after a chase, say police.
The officer fired 17 shots at the teenager, police added.
Two months ago a fatal shooting in the nearby suburb of Ferguson sparked weeks of unrest and international headlines.
Michael Brown, 18, was unarmed when he was killed by a white officer, who could face criminal charges.
Angry crowds on Shaw streets after an off-duty police officer fatally shot a black teenager (photo AP)
The latest incident began when the officer, dressed in his city police uniform, spotted three men running away from him in Shaw neighborhood, says St Louis Police Chief Colonel Sam Dotson.
The 32-year-old officer thought one of the men was carrying a weapon so chased him and a confrontation followed.
During the altercation, the man fired at the officer, who returned fire and killed him, said Sam Dotson.
Ballistic evidence suggests the man fired three rounds at the officer before his weapon jammed, and a gun was recovered from the scene, he added.
The officer, who was not injured, fired 17 shots, said Sam Dotson.
“An investigation will decide if the officer’s behavior was appropriate,” he said at a news conference in the early hours of Thursday, October 9.
Neither man has been named.
Hours after the shooting, a crowd gathered at the scene, with some shouting “hands up, don’t shoot”, in reference to the fatal shooting of Michael Brown by a white policeman on August 9.
Some police cars were damaged but there were no arrests.
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Protesters and police have clashed again in Ferguson, Missouri, during a fourth night of unrest since black teenager Michael Brown was shot dead by police.
Crowds gathered in the St Louis suburb on Wednesday night despite a police order to leave by the end of the day. Tear gas was fired at angry protesters.
Eyewitnesses have said Michael Brown, 18, had his arms raised when he was shot dead by an officer on Saturday.
Police say there was a struggle and the officer suffered facial injuries.
Earlier on Wednesday, the St Louis County Police Department asked protesters to gather only in the daylight hours and to disperse “well before the evening hours” for safety reasons.
The plea came after three nights of tense, sometimes violent protests that resulted in dozens of arrests, looting and the burning of a shop.
Protesters and police have clashed again in Ferguson, Missouri, during a fourth night of unrest since black teenager Michael Brown was shot dead by police (photo AP)
Despite this appeal to stay away, and an earlier call for calm from President Barack Obama, the anger seemed as palpable as ever on the streets of Ferguson on Wednesday night.
Heavily armored vehicles blocked off streets and protesters linked arms defiantly as they were told through loudspeakers to leave the area or face arrest.
Molotov cocktails were thrown at lines of police and they launched smoke bombs and fired tear gas.
Two journalists were briefly detained by police earlier on Wednesday while working inside a McDonald’s restaurant.
One of them, Wesley Lowery of the Washington Post, later tweeted: “Apparently, in America, in 2014, police can manhandle you, take you into custody, put you in cell & then open the door like it didn’t happen.”
Civil rights activists and Michael Brown’s family and friends have called for an end to violent clashes with the police, while also demanding the Ferguson police department release the name of the officer who shot and killed the teen.
Police say the officer has not been named because his life would be in danger.
President Barack Obama has promised a full investigation by the US Department of Justice into Michael Brown’s death, and the FBI has launched its own inquiry.
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