Videos showing officials forcibly removing a man from a United Airlines flight on April 9 have caused a stir because of the graphic nature in which he was taken off the flight.

The removal was caught on video by numerous passengers aboard plane and shows three security officers speaking with a man before yanking him into an aisle and dragging him off of the plane amidst screams from other passengers.

Watch a video of two separate angles of the incident caught by two passengers below.

The United flight was bound for Louisville out of O’Hare International Airport in Chicago. The reason the passenger was removed was because flight 3411 was overbooked, United said in a statement released Monday. It added that the passenger “refused” to get off of the plane after being asked to voluntarily do so.

United CEO Oscar Munoz also released a statement Monday saying that the incident is “upsetting.” He added that the airline will investigate and review the incident.

The Chicago Department of Aviation said in a statement that the incident on board the plane “was not in accordance” with the standards of the group. The officer who removed the man from the plane has been placed on leave, it said in its statement.

According to the Louisville Courier-Journal, passengers at the gate before the flight were told that it was overbooked. United offered a $400 credit and a hotel stay if passengers would re-book and fly to Louisville on Monday afternoon. Crews allowed the plane to be boarded until it was at capacity.

A United staff member reportedly got onto the plane and told passengers that four people had to give their seats up to United employees that required to be in Louisville on Monday. Nobody volunteered to do it, so staff randomly selected passengers.

The first two were a couple, who got off the plan without incident.

The next was the man, who said he would be unable to get off the plane because of a commitment in Louisville in the morning, reports say.

According to Twitter user JayseDavid, the man, who is said to be a doctor, had his face “slammed” against an arm rest, which caused the blood to flow from his mouth. He added that it appeared as if the man was “knocked out” because his body suddenly went limp. After about 10 minutes, the man ran back onto the plane looking disoriented with his face bloodied. Passengers say he clung to an object in the back of the plane, screaming “I need to go home” before he was removed once again.

The flight was delayed around two hours before it finally took off for Louisville.