Tensions between protesters and police in Missouri have mounted during a fourth night of unrest since a black teenager was shot dead by police.

Crowds gathered in Ferguson last night despite a police order to leave by the end of the day. SWAT teams and police have been using tear gas, smoke bombs and rubber bullets to disperse angry protesters.

There has been looting and vandalism in the city over the last few days, as protests continue over the death of Michael Brown. 

Eyewitnesses have said 18-year-old Michael Brown, who was unarmed, had his arms raised when he was shot dead by an officer on Saturday. 

Police authorities have disputed this account. They say there was a struggle and the officer suffered facial injuries.

Protesters have been calling for the officer who shot Brown to be fired and charged.

Michael Brown's father has called for justice - saying he "was a good boy" who "deserved none of this".

The FBI and the US Justice Department have opened an investigation into the teenager's death.