A Louisiana police officer was fired and a second suspended for the killing of Alton Sterling, a black man shot in a 2016 incident that inflamed the US debate on racial bias in law enforcement, a police official said.

Baton Rouge officer Blane Salamoni, who shot Sterling in a confrontation outside a convenience store, was dismissed for violating department standards on use of force and for losing his temper, Police Chief Murphy Paul told a news conference.

The second officer, Howie Lake, was suspended for three days for failing to maintain his composure. The decisions followed an administrative review of the July 2016 shooting, and both officers plan to appeal, Paul said.

The steps are designed "to bring closure to a cloud that has been over our community for far too long," he said.

Sterling was among black men slain by police whose deaths sparked US protests and helped fuel the Black Lives Matter movement.

Police released four videos of the confrontation with Sterling outside a convenience store, where he was selling CDs.

Paul called the footage from a police dash camera, officers' body cameras, and a store surveillance camera "graphic and shocking to the conscience."

Salamoni's camera shows him yelling at Sterling with expletives to put his hands on a car. He points a gun at his Sterling's head and shouts he will shoot him if he moves.

While struggling with Sterling, both officers' cameras came loose. Lake's footage ends by showing Sterling on his back in the parking lot, blood draining from his body.

Sterling, 37, was shot after a resident reported he had been threatened by a black man selling CDs. Police said Sterling was trying to pull a loaded gun out of his pocket when Salamoni opened fire.