"The truly horrific event that occurred on this flight has elicited many responses from all of us: outrage, anger, disappointment,” CEO Oscar Munoz said in a statement Tuesday. “I share all of those sentiments, and one above all: my deepest apologies for what happened.”

The statement comes after an earlier apology “for having to re-accommodate these customers” did nothing but further exasperate denizens of the online community.

Videos of the incident show airport security wrenching a passenger from his seat and dragging him down the aisle on a flight from Chicago, Illinois to Louisville, Kentucky.

The passenger has since been identified in media reports as David Dao, a doctor from Elizabeth, Kentucky.

The disturbing episode began when the airline offered as much as $800 to passengers who would give up their seats, but not enough people volunteered, prompting a random selection, according to the United Airlines.

After three people agreed to leave, Dao said he was a doctor and he could not give up his seat because he had appointments to keep the following day.

Airport law enforcement then came in and forcibly removed him, ignoring his screams and bloodying his face by causing him to apparently hit his head on an armrest.

In the videos, one of the passengers is heard anxiously screaming: “No! This is wrong. Oh my God! Look at what you did to him.”

One of the security officers involved in removing Dao has been suspended, Chicago Department of Aviation said in a statement.

It said the officer’s actions were “obviously not condoned by the department”, and promised a review of the incident.

Another video that surfaced Tuesday shows a rattled Dao back on the plane, standing in the aisle and muttering repeatedly, “Kill me, just kill me”.

Munoz’ earlier statement Monday was more defensive of the crew’s reaction, calling Dao’s refusal to leave “disruptive and belligerent”.

Faced with intense backlash, he said in Tuesday’s statement: “Like you, I continue to be disturbed by what happened on this flight and I deeply apologize to the customer forcibly removed and to all the customers aboard.

“No one should ever be mistreated this way,” Munoz added.

It emerged Tuesday that the flight, earlier described by the airline as overbooked, had only been fully booked, meaning there was room for everyone.

However, the company needed to transport four of its employees who would be working in Louisville the next day, hence the re-accommodations.

"I want you to know that we take full responsibility and we will work to make it right,” the statement said.

"It's never too late to do the right thing. I have committed to our customers and our employees that we are going to fix what's broken so this never happens again,” it added.

Anadolu Agency