A video taken in Cambridge, Massachusetts, has been called “disturbing” by the mayor for showing a violent encounter between a police officer and an unarmed, naked Black Harvard University student.

In the video, released by the Cambridge Police Department, a police officer is seen repeatedly striking Selorm Ohene, 21, while he was pinned to the ground by fellow officers on Friday night. The mayor of Cambridge said an investigation of the video will take place and the findings will be shared with the public.

“Cambridge affirms that Black lives matter, but it must be true in practice as well,” Mayor Marc C. McGovern said in a statement Sunday morning.

In the video, Ohene is standing on a grass median when three Cambridge officers and an MBTA Transit Police officer approach. As Ohene approaches one of the officers, another officer grabs the student’s legs while the other officers pin him to the ground.

Ohene was naked, and a woman who appeared to be Ohene’s friend told officers he may have been on drugs, reported the Boston Globe.

In the video, shot by a bystander and released by police, Ohene is surrounded by three officers, then turns and approaches one of them.

While pinned to the ground, Ohene can be heard on the video yelling, “Help me, Jesus! Help me, Jesus!” Eventually, a fourth officer helps restrain Ohene while another one can be seen punching the student. 

Ohene was charged with indecent exposure, disorderly conduct, assault, resisting arrest, and assault and battery on ambulance personnel, police said.

City Councilor Sumbul Siddiqui also called the video disturbing and said it raises questioned about whether punching is a justifiable use of force by police.

“I think when you see the video and you see the officer punch the individual after he’s subdued, you think, ‘What kind of protocol was that?’” Siddiqui told The Globe on Sunday.

Police said they told Ohene they were “only there to help him and were concerned for his safety,” according to the police report. Police said Ohene became “aggressive, hostile, and intimidating” and approached officers with fists, forcing them to take action.

However, no officers were struck during the arrest. In fact, an officer struck Ohene five times in the torso, according to the police report.