© Reuters/Mario Anzuoni A protester throws back a smoke bomb while clashing with police in Ferguson
As anger over black teenager's death escalates, Barack Obama has been criticised for staying away on holidayPolice have begun using tear gas, stun grenades and rubber bullets on those protesting the shooting of an unarmed black teenager in Ferguson, Missouri, as another witness said Michael Brown was backing away with his hands up as an officer repeatedly fired at him.
The situation in the suburb of St Louis has rapidly deteriorated following largely peaceful vigils on Tuesday night, and has led to calls for Barack Obama to cut short his golfing holiday to Martha's Vineyard in Massachusetts.
Last night some protesters were seen hurling rocks at the heavily-armed and camouflage-wearing police units, while there were reports of young men preparing what appeared to be petrol bombs in a bus shelter.
Angry protests have taken place in Ferguson every night since Saturday, when the 18-year-old was shot to death in what police say was a struggle over a gun in a police car.
A new witness, Tiffany Mitchell, told CNN she was watching when Mr Brown and an officer, who has not been named, were "tussling through the window".
Ms Mitchell said the officer was pulling the teen in as he struggled to get away, and then "a shot was fired through the window".
"The kid finally gets away and he starts running. As he runs, the police get out of his vehicle and he follows behind him shooting," Mitchell said, adding that Brown turned around and put his hands in the air.
"The cop continued to fire until he just dropped down to the ground and his face just smacks the concrete."
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