CHICAGO  — Video of police officers dragging a passenger from an overbooked United Airlines flight sparked an uproar Monday on social media, and a spokesman for the airline insisted that employees had no choice but to contact authorities to remove the man.

As the flight waited to depart from Chicago’s O’Hare Airport, officers could be seen grabbing the screaming man from a window seat, pulling him across the armrest and dragging him down the aisle by his arms. The airline was trying to make room for four of its employees on the Sunday evening flight to Louisville, Kentucky.

Other passengers on Flight 3411 are heard saying, “Please, my God,” ‘’What are you doing?” ‘’This is wrong,” ‘’Look at what you did to him” and “Busted his lip.”

Passenger Audra D. Bridges posted the video on Facebook. Her husband, Tyler Bridges, said United offered $400 and then $800 vouchers and a hotel stay for volunteers to give up their seats. When no one volunteered, a United manager came on the plane and announced that passengers would be chosen at random.

“We almost felt like we were being taken hostage,” Tyler Bridges said. “We were stuck there. You can’t do anything as a traveler. You’re relying on the airline.”

Bridges said that about 7 or 8 minutes later the man hurried down the aisle of the plane to the back of the aircraft and another video, showing the man, his lip bleeding and blood on his mouth, chin and cheek and appearing dazed as he said, “I want to go home, I want to go home.”

When airline employees named four customers who had to leave the plane, three of them did so. The fourth person refused to move, and police were called, United spokesman Charlie Hobart said.

“We followed the right procedures,” Hobart told the Associated Press in a phone interview. “That plane had to depart. We wanted to get our customers to their destinations.”

Oscar Munoz, CEO of United Airlines’ parent company, described the event as “upsetting” and apologized for “having to re-accommodate these customers.” He said the airline was conducting a review and reaching out to the passenger to “further address and resolve this situation.”

The passenger told the manager that he was a doctor who needed to see patients in the morning, Bridges said.

“He was kind of saying that he was being singled out because he’s a Chinese man” when speaking to the manager, who was African-American, Bridges said.