Police in the US state of Missouri have clashed with protesters for a fourth night amid growing anger at the fatal shooting of a black teenager by police.
Heavily armed riot police fired tear gas as they moved in on demonstrators in Ferguson, St Louis, who had ignored an order to disperse.
The tension was sparked by the death of Michael Brown, 18, on Saturday.
Details about the incident have been disputed but eyewitnesses said the unarmed teenager had his arms raised when he was shot multiple times by a police officer.
Police say there was a struggle and the officer suffered facial injuries.
The St Louis County Police Department had asked protesters on Wednesday 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.
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.
Armoured vehicles blocked off streets and protesters linked arms defiantly as they were told through loudspeakers to leave the area or face arrest.
The demonstrators chanted: “Hands up, don’t shoot.”
Molotov cocktails were thrown at lines of police, who launched smoke bombs and fired tear gas.
Two US 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.”