WARNING: GRAPHIC MATERIAL

Police in Fresno, California have released body camera videos showing two officers fatally shooting an unarmed white man amid renewed scrutiny across the United States over the use of force by police.

Dylan Noble was shot and killed on June 25 during a traffic stop by two unidentified police officers who thought the 19-year-old was armed, Fresno Police Chief Jerry Dyer said.

He said the decision to release the footage was based on public concern over how police handled the incident, which has sparked protests.

The videos show Noble getting out of a pick-up truck during the traffic stop and failing to comply with officers' commands several times.

Dyer said one of the officers told investigators he thought Noble was either taunting him or was practicing pulling out a gun, although it later emerged Noble wasn't armed.

An officer twice shot Noble, who fell to the ground. He then fired a third round at Noble as he was reaching again under his shirt and into his waistband.

A second officer shot Noble when he again reached into his waistband, the video showed.

Dyer said questions remain whether the last two shots that were fired by police when Noble was lying on the ground were necessary. A criminal and an internal affairs investigation are ongoing.

The release of the videos comes as police are under sharp scrutiny across the country over high-profile police killings of unarmed black people, sparking widespread and sometimes destructive protests.