One of the officers involved in forcibly removing and dragging a passenger from an overbooked United Airlines flight was placed on leave Monday.

“The incident on United flight 3411 was not in accordance with our standard operating procedure and the actions of the aviation security officer are obviously not condoned by the Department,” a spokesperson for the Chicago Department of Aviation told TIME. “That officer has been placed on leave effective today pending a thorough review of the situation.”

The spokesperson did not provide any other details of the decision or the incident itself. It was not clear how many officers were involved in the incident.

In a statement, the Chicago Police Department said Aviation officers were summoned to the aircraft after the passenger “became irate after he was asked to disembark from a flight that was oversold.”

“Aviation Officers arrived on scene attempted to carry the individual off of the flight when he fell,” the police said. “His head subsequently struck an armrest causing injuries to his face.”

Other videos taken by passengers show the man repeatedly saying, “just kill me, just kill me” as blood dripped from his head and mouth during the incident. Police said he was taken to the hospital with non-life threatening injuries.

A video posted on Facebook Sunday evening showed a security officer pulling a passenger from his seat and dragging him by the arms through the aisle of an overbooked United Airlines flight heading from Chicago to Louisville.

The man had refused to leave his seat after United officials randomly selected four passengers to switch flights to allow four United employees to take their places on board, passenger Audra Bridges, who took the video, told Courier-Journal. The male passenger claimed he was a doctor who had to return to his patients Monday morning. (The company had offered vouchers and hotel stays to a volunteer to take a Monday flight, but no one opted to do so.)

The incident evoked outrage online as people questioned the handling of the incident by United Airlines and security officers involved.

“After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate,” the company said in a statement Monday morning.

United CEO Oscar Munoz said the company will conduct a review “with a sense of urgency” and will speak with the man who was pulled from his seat.

“I apologize for having to re-accommodate these customers,” Munoz said.

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