Chicago: The social media storm prompted by footage of United Airlines forcibly removing a passenger from an overbooked flight continued to spread Tuesday with accusations of perceived racism and calls for a boycott of the US carrier.

The videos taken on the plane and posted to Twitter showed the man, reportedly identified by another passenger as ethnically Chinese, being forcibly pulled screaming from his seat by three security personnel.

The incident occurred Sunday on a United Express flight from Chicago to Louisville, Kentucky. Such flights are operated by one of eight regional airlines that partner with United.

The airline said it had asked for volunteers to give up their seats, and police were called in after one passenger refused to leave the plane.

Smartphone video posted online showed three Chicago Department of Aviation police officers struggling with a seated middle-aged man.

He starts to scream as he is dragged off while other passengers look on — some recording the event with their phones.

One passenger can be heard yelling, ‘Oh my God, look at what you did to him!’

The showdown quickly ignited social media outrage, with ‘United’ a trending term on Twitter, Facebook and Google.

The footage was also re-posted on China’s Twitter-like Sina Weibo, where the incident quickly became the top trending topic, garnering more than 120 million views and 80,000 comments.

‘Shameless! We won’t forgive them. Ethnic Chinese around the world please boycott United Airlines!’ wrote one commentator.

United Airlines claims to be the biggest carrier to China, with more nonstop US-China flights to more Chinese cities than any other airline, according to the company’s website.

‘Upsetting for all’

In a statement late Monday, the Chicago Department of Aviation said the incident was ‘not in accordance with our standard operating procedure and the actions of the aviation security officer are obviously not condoned by the department.’

‘That officer has been placed on leave effective today pending a thorough review of the situation,’ the statement said.

It was another example of bad press and negative social media coverage for United after an incident in late March in which two teenage girls were prevented from boarding a flight in Denver because they were wearing leggings.

The airline defended its action at the time by saying the girls were flying on passes that required them to abide by a dress code in return for free or discounted travel.

Speaking to various media outlets about Sunday’s incident, the airline said it had asked for volunteers to leave the overbooked plane.

‘One customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate,’ United spokesman Charlie Hobart was quoted by the Chicago Tribune newspaper as saying.

United did not return AFP’s request for comment, but the airline addressed the incident in a statement posted on its website on Monday.

‘This is an upsetting event to all of us,’ said chief executive Oscar Munoz, noting that the airline was conducting a ‘detailed review of what happened.’

‘We are also reaching out to this passenger to talk directly to him and further address and resolve this situation,’ he said.

Passengers ‘disturbed’

Tyler Bridges, who posted footage of Sunday’s incident on Twitter, said the man appeared to be bloodied after his encounter with the law enforcement officials.

Bridges also posted video showing the man running back on the plane, repeatedly saying, ‘I have to go home.’ He appeared to be pacing and disoriented.

‘Not a good way to treat a doctor trying to get to work because they overbooked,’ he wrote.

He described passenger reaction on the plane as ‘disturbed’ saying: ‘Kids were crying.’

US airlines are allowed to involuntarily bump passengers off overbooked flights, with compensation, if enough volunteers cannot be found, according to the Department of Transportation.