The shooting death of an unarmed black man by a white police officer in Atlanta area of Georgia State has prompted a social media outcry and an investigation on whether the use of force is necessary.

Anthony Hill, 27, who died in DeKalb County Monday afternoon, is the latest victim of police killings of unarmed black men in the United States.

Hundreds of people turned to Twitter to express frustration over the fatal shooting, using hashtags #AnthonyHill and #BlackLivesMatter.

DeKalb County police Chief Cedric Alexander said it appeared Hill was experiencing some type of mental health issue when police received a call about a man "acting deranged, knocking on doors, and crawling around on the ground naked."

Alexander said Hill ran toward a responding officer, who ordered him to stop before firing at him twice. Hill died at the scene and the police found no sign of a weapon.

Hill had been having problems with medication that he took, the New York Times quoted Harrietta Jones, one of his relatives, as saying.

The county police chief said the agency turned over the shooting investigation to the Georgia Bureau of Investigation due to transparency and fairness considerations.

Last year, public outcry and national protests were triggered when a white police officer shot unarmed black teenager Michael Brown in Ferguson, Missouri in August and was not indicted afterwards.

The US Justice Department launched an investigation into Ferguson's police department and municipal court and found sysmetic racial bias.