Ferguson protests heat up as jury nears decision on Michael Brown charges

US President Barack Obama has called for calm in the Missouri town of Ferguson as a grand jury draws closer to deciding whether or not to charge a police officer over the fatal shooting of an unarmed black teen.

Michael Brown, 18, was shot dead in Ferguson by white police officer Darren Wilson on August 9.

Protestors have been assembling to demand charges be laid against Mr Wilson.

Mr Obama, who has previously used the shooting incident to talk about racial issues in America, urged the protestors to remain within the bounds of the law.

"First and foremost, keep protests peaceful," he said.

"This is a country that allows everybody to express their views, allows them to peacefully assemble to protest actions that they think are unjust, but using any of that as an excuse for violence is contrary to rule of law, contrary to who we are."

Brown was killed by multiple gunshot wounds, sparking riots and looting in Ferguson in the following days.

Police originally said the teen was a theft suspect who had wrestled with Mr Wilson for his gun.

However, multiple witnesses said Brown had surrendered and was kneeling with his hands behind his head when he was shot.