A citizen accountability group is investigating after a Chicago police officer was recorded body-slamming a man on the street during an arrest on Thanksgiving Day.

In a now-viral video posted to Facebook, the officer is seen grabbing a man in a black hoodie and jeans by the waist and throwing him to the ground, causing his head to hit the sidewalk curb. The man lies on the street, motionless, for the remainder of the 43-second video as another officer stands over him.

The incident, which occurred Thursday afternoon, is being investigated by the Civilian Office of Police Accountability. The officer in the video has been "relieved of police powers" pending the investigation, Chicago police spokesperson Anthony Guglielmi said Friday.

"The incident is under investigation as the actions in the video are concerning," police said in a statement. "If wrongdoing is discovered, officers will be held accountable."

Guglielmi told BuzzFeed News the man was thrown to the ground after allegedly licking an officer's face and spitting in his eye and mouth. Police were attempting to arrest the man for allegedly drinking in public in the 700 block of East 79th Street.

The spokesperson said the 29-year-old, whose name has not been released, was treated at the University of Chicago Medical Center for minor injuries.

He was released from the hospital later that evening and taken into police custody on suspicion of aggravated battery to a police officer and drinking in a public way.

Guglielmi said the man has not yet been charged. He was still in custody midday Saturday.

In a series of tweets on Friday morning, Chicago Mayor Lori Lightfoot said that she had watched the video, calling it "very disturbing."

"While a single video does not depict the entirety of the interactions between the police and the individual, this particular video is very disturbing," Lightfoot said. "It is my expectation that the investigation will be comprehensive and expedited so that the public may gain a complete picture of what happened."

Jovonna Jamison, a bystander who recorded the video, told the Chicago Tribune she was waiting at a red light when she saw an officer snatch the man's beer away, adding that he was on the phone when the officer picked him up and threw him to the ground.

“I’m not really surprised because it happens so much in Chicago, but I didn’t think I would ever see it front and center,” Jamison said.