One of the officers who dragged a United Airlines passenger off a plane has been placed on leave

A police officer who dragged a passenger off a United Airlines flight has been placed on leave, a Chicago Aviation Department spokesperson told Business Insider.

A video showing three police officers forcibly removing a male passenger from a plane traveling from Chicago to Louisville went viral Monday, sparking outrage on social media.

The 69-year-old Asian male was removed after refusing to give up his seat on the flight, the Chicago Aviation Department wrote in a statement. United Airlines says it first asked for volunteers to leave the plane in exchange for $800 and then told several passengers they must leave after no one volunteered.

When the male passenger refused to give up his seat, police officers pulled him off the plane, resulting in injuries to his face. The man was treated for his injuries at a local hospital.

"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. That officer has been placed on leave effective today pending a thorough review of the situation," a spokesperson for the Chicago Aviation Department wrote in an email to Business Insider.

The spokesperson did not immediately clarify why only one of the three officers involved in the incident was placed on leave.

The police officers involved in the incident work for the Chicago Aviation Department, which is not affiliated with the Chicago Police Department, a Chicago P.D. spokesperson told Business Insider.

United Airlines provided the following statement to Business Insider:

"Flight 3411 from Chicago to Louisville was overbooked. After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate. We apologize for the overbook situation. Further details on the removed customer should be directed to authorities."

United CEO Oscar Munoz released a statement about the incident as well:

"This is an upsetting event to all of us here at United. I apologize for having to re-accommodate these customers. Our team is moving with a sense of urgency to work with the authorities and conduct our own detailed review of what happened. We are also reaching out to this passenger to talk directly to him and further address and resolve this situation."