An Atlanta police officer has been caught on camera punching a defenseless suspect repeatedly in the head.

Both the officer - who is not being named by authorities - and the suspect are black. The June 22 arrest was filmed and then posted online by Black Lives Matter of Greater Atlanta, which is calling for the cop's termination.

'Black men aren't safe in Atlanta,' BLM GA presdient Sir Maejor wrote. 'This is what I call a #BlueOnBlackCrime, as an organization, we stand against police brutality regardless the color of the officer.'

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A shocking act of violence was filmed in Atlanta on June 22, as a black suspect was held down by two cops and punched in the head by a third. All of the men involved are black

The video shows the suspect being held down by two other cops and watched by a fourth as he is struck. All police on the scene are black.

After the first punch to the head, the suspect writhes on the ground; after the second he cries out 'Stop!'

Criminal defense attorney Page Pate told 11 Alive that 'police officers have a legal right to use force to make an arrest if the arrest is lawful.'

'But they can only use so much force as is required to make an arrest,' said Pate, who has been an attorney for 23 years.

'They had the guy on the ground,' he added. 'He may not have completely been complying with all of their requests, but they had him completely under control. He posed a danger to no one.

'From what I saw in the video, the officer was acting with excessive force.'

The video was posted to the Black Lives Matter of Greater Atlanta page. A fourth cop (seen right), also black, watched. The officer who hit the suspect has been suspended

However, Bill McKenney - an attorney and ex-police officer - told the channel that the cop was using 'pain compliance' in line with his training.

He notes that the suspect appears to have a handcuff on one wrist, suggesting that he had broken away from the officers once the cuffs were put on him.

'Once the suspect became active, that officer was allowed to use reasonable force,' McKenney said. 'He did not club him; he did not kick him. He used what is taught in the academy, which is a closed slap, to get compliance.

'It's a form of pain compliance and I didn't see unreasonable force.'

Atlanta police said in a statement: 'The officer involved in the use of force depicted in the video has been relieved of duty and is currently on administrative leave.

'Following the conclusion of the internal investigation, Chief Erika Shields will review the evidence therein to determine the appropriate disciplinary action, if any.

'Chief Shields has always held professionalism and honesty in high regard and will continue to hold her officers to the highest standard.'

Commenters on Greater Atlanta's Black Lives Matter Facebook page were incensed by the video.

Tyrone Carter said the PD's statement 'means nothing without the conviction.'

Eddie Ingram wrote: 'Crazy part is they will b punished fired and debadged, which is wat should happen, bt if the cops are white they will b BK to work next Monday.'

'Their job is to arrest not assault! Resisting a lawful or unlawful arrest does not warrant them punching and or kicking a person!' wrote Jay Calloway.

'That is assault. You detain them without all of that and if you cant do that with 400 officers present then you need to find another profession.'