All hell broke loose aboard an overbooked United Airlines flight when a passenger reportedly refused to give up his seat.

Video of the distressing incident surfaced on social media Sunday night that showed security personnel forcibly remove the middle-aged man.

Amid being lifted from his seat, the screaming passenger appeared to bang his face off an elbow rest, leaving him bloodied and dazed.

Officials then dragged the man down the aisle and off the plane as distressed passengers watched in horror.

“Oh my God!” one passenger screamed. “No! My God, what are you doing? This is wrong. Look at what you did to him.”

United later confirmed to WHAS 11 in Louisville that the flight was overbooked and that the airline had asked for volunteers to give up their seats. When nobody volunteered, the airline asked a handful of passengers to forfeit their seats – including the man seen in the video.

But the passenger reportedly refused to budge after claiming he was a doctor who needed to get home to his patients.

“A couple air port security men forcefully pulled the doctor out of his chair and to the floor of the aisle,” tweeted Jayse Anspach, a fellow passenger.

@united@FoxNews@CNN not a good way to treat a Doctor trying to get to work because they overbooked pic.twitter.com/sj9oHk94Ik — Tyler Bridges (@Tyler_Bridges) April 9, 2017

“In so doing, the doctor's face was slammed against an arm rest, causing serious bleeding from his mouth.

“It looked like he was knocked out, because he went limp and quiet and they dragged him out of the plane like a rag doll."

Ten minutes later, the man reportedly darted back onto the plane and continued pleading with staff to let him go home.

The airline later confirmed in a statement that a passenger aboard Flight 3411 – which was delayed by two hours – refused to leave the aircraft, at which time security was called.

“Flight 3411 from Chicago to Louisville was overbooked,” United said in a statement. "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 apologise for the overbook situation.”

This is just the latest United incident to draw ire from passengers.

United also came under fire last month when it denied a pair of teenage girls seats on a flight due to their attire.

The airline later clarified that the girls’ attire -- they were wearing leggings -- violated the company’s travel pass dress code.