An aviation security officer who dragged a passenger off a United Airlines flight in Chicago has been placed on leave for not following protocol.
Footage taken inside the airliner showed a passenger being ripped out of his seat and dragged down the aisle as the plane prepared to take off from Chicago to Louisville on Sunday evening.
Videos showing a man being removed provoked an outcry on social media. One 50-second clip of the incident on Twitter was re-tweeted 16,000 times since it was posted that day.
The airline has apologised, and the Department of Aviation said the officer - one of three involved in the incident - did not follow protocol
As a result, the officer has been placed on leave, pending a "thorough" review.
"The actions of the aviation security officer are obviously not condoned by the Department," the statement said.
Jayse D Anspach, who posted the footage, tweeted:
"United overbooked and wanted four of us to volunteer to give up our seats for personnel that needed to be at work the next day.
"No one volunteered, so United decided to choose for us. They chose an Asian doctor and his wife."
"The doctor needed to work at the hospital the next day, so he refused to volunteer," Mr Anspach added.
"Ten minutes later, the doctor runs back into the plane with a bloody face, clings to a post in the back, chanting, "I need to go home."
United Airline tweeted an apology for what happened and said it was investigating.
United CEO response to United Express Flight 3411. pic.twitter.com/rF5gNIvVd0— United (@united) April 10, 2017
Another passenger Audra D. Bridges, posted a video of the incident on Facebook that has been viewed over 400,000 times.
She wrote: "We are on this flight ...they randomly selected people to kick off so their standby crew could have a seat.
"This man is a doctor and has to be at the hospital in the morning," she added. "He did not want to get off. We are all shaky and so disgusted."
Thousands of Facebook comments have been posted about what happened.
One person wrote: "This is infuriating"
Another posted: "OMG So sad to see someone being treated like this. I wont fly United ever again."
But another felt the video raised some unanswered questions.
"There has to be more to this story," he said.
"Usually when a flight is overbooked they offer free flight vouchers to those willing to change flights or go on standby and a couple of people will jump at those as their travel plans may be flexible."
"I feel like this specific incident HAS to be deeper than what we are seeing in this video," he added.
In a statement United airlines told the BBC: "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," the airline added.
The chief executive of United, Oscar Munoz, later made a statement on Twitter: "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 the situation," he added.