George Zimmerman, the Florida neighbourhood watchman who shot dead an unarmed black 17-year-old male last year, has been found not guilty, BBC News reported.

Lawyers for Zimmerman, 29, argued he acted in self-defence and with justifiable use of deadly force in the death of Trayvon Martin.

The jury retired on Friday, July 12 to consider its verdict on charges of either second-degree murder or manslaughter.

The case sparked a fierce debate about racial profiling in the U.S.

Protesters are gathering, reports the BBC's David Willis, in Sanford, the Florida town where the shooting took place.

Police and community leaders have appealed for calm.