The Ferguson protests

Protests broke out in Ferguson after 18-year-old Michael Brown was shot and killed while walking down a residential street in the Missouri town in the afternoon. The officer who shot him has been identified as Darren Wilson, 28.

Accounts of Brown's slaying differ sharply. According to police, Wilson reported that Brown reached into the policeman's cruiser when Wilson approached him on the street, then grabbed for the officer's gun.

A companion of Brown said the teenager was initially shot after the officer tried to grab him through the car window and again after Brown staggered back with his hands in the air.

An independent autopsy arranged by Brown's family found he had been shot six times, including twice in the head.

Many protesters have demonstrated against his death with their arms in the air, chanting “hands up, don’t shoot”.

In this image, a protester throws back a smoke bomb while clashing with police in Ferguson.

The demonstrations, mostly peaceful but with spasms of violence, looting and vandalism by smaller groups, have captured headlines around the world.

They have exposed simmering racial tensions in a mostly black town whose police force, political leadership and public education administration are dominated by whites.

Here, riot police clear demonstrators from a street in Ferguson.

The unrest in the town has re-ignited a national debate over racial disparities in the U.S. criminal justice system, even drawing sharp words from the United Nations' top human rights envoy, Navi Pillay.

"I condemn the excessive force by the police and call for the right of protest to be respected," she said in Geneva.

On Aug. 14, Missouri State Highway Patrol Captain Ron Johnson (pictured above) was placed temporarily in command of police in Ferguson.

Johnson, who grew up in the town, said he would take a "different approach" to policing after complaints that officers used heavy-handed tactics.

His appointment did not immediately put a halt to unrest, however. On the night of Aug. 18 and early Aug. 19, at least 57 people were arrested in Ferguson, most accused of disobeying police orders to disperse.

Clashes that night were marked by volleys of tear gas fired at demonstrators and rocks and bottles and gasoline bombs hurled at police. Johnson said officers also had come under "heavy gunfire" on the night of Aug. 18 but did not return it.

Lesley McSpadden, the mother of the dead teenager Michael Brown, holds up a drawing of her son while leaving a news conference in St. Louis.

Brown's family and supporters have called for the arrest of the officer who shot him.

McSpadden spoke out in a televised interview with ABC's "Good Morning America" programme, saying peace could be restored "with justice... arresting this man and making him accountable for his action."

The unrest in Ferguson following Brown’s shooting has drawn attention both across the United States and abroad. In the image above, people attend a vigil in honour of the dead teenager in New York.

The St. Louis County prosecutor's office is expected to begin presenting evidence to a grand jury investigating Brown’s death, in a case that Missouri Governor Jay Nixon vowed would be treated as a "vigorous prosecution."