A video showing a United Airlines passenger being dragged out of his seat by Chicago policemen due to overbooking on Sunday has sparked social media outrage. The flight was leaving Chicago’s O’Hara airport for Louiseville in Kentucky. The airline had apologised for the “overbook situation” and because the customers had to be re-accommodated, but it did not apologise for the incident.

The airline was overbooked and also had to accommodate four of its employees on the flight. After no one volunteered to deboard the plane, a United manager named four passengers at random who were asked to leave and were offered $400 vouchers as compensation. However, only three of the four left the aircraft.

“After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate,” United said in a statement on Sunday. In the video of the incident, police officers can be seen forcibly pulling a man out from his window seat and then dragging him down the aisle by his arms. The passenger’s name was David Dao, USA Today reported.

In an email to his team, Chief Executive Officer of the airline, Oscar Munoz, said that the authorities had been forced to act after Dao turned “disruptive and belligerent”. They had no choice but to call the Chicago Aviation Security Officers and remove Dao from the flight, he said. The passenger is believed to be a doctor who had to fly to Louisville to see his patients.

One of the eyewitnesses – Tyler Bridges, who also posted a video on Twitter of the incident – told The New York Times that Dao had alleged he had been singled out because he was Chinese. He was also injured while being dragged off the flight. The flight was delayed by a few hours because all passengers were deboarded so that the flight could be cleaned of what was reported to be Dao’s blood.

The Chicago Aviation Department has placed one of the police officers involved in the incident on leave. The Department added that the incident “was not in accordance” with their standard operating procedure, NYT reported.

This incident comes weeks after the airlines was in the middle of a controversy for barring two girls from boarding a flight because they were wearing leggings.