United overbooking story tops Chinese social media on evicted passenger's claim he was singled out for ethnicity

United Airlines faces social media backlash in China

Viral videos showing a passenger who appears to be of Asian ethnicity dragged off an overbooked United Airlines plane by security officers has triggered outrage on social media on China.

The viral video was posted on Facebook by fellow passenger Audra D. Bridges, who told the Associated Press she heard the man "saying that he was being singled out because he's a Chinese man."

The man who was forcibly evicted from his seat has not been identified and has not commented publicly. His identity as ethnic Chinese could not be confirmed. United did not immediately respond to an emailed request for comment.

But on microblog Weibo, China's answer to Twitter, the top trending topic on Tuesday was #UnitedAirlinesforcespassengeroffplane with most users expressing shock and anger at the video while some called for a boycott of the carrier.

Video shows man being forcibly removed from United Airlines flight

In a post on his verified Weibo account that generated some 50,000 likes in over three hours, Chinese American comedian Joe Wong said the passenger who reportedly said he was selected for being Chinese deserves a "thumbs up" as many Chinese who feel discriminated against don't say it out loud so as not to lose face.

"This results in the Western mainstream media and public not taking discrimination against Asians seriously," he added.

Another Weibo user, Koukou Liang said: "Whether the passenger is Asian or not, this is abominable." Some accounts on Weibo go under other handles, such as User7935599911 who said:

"No need to apologize or explain...please sue United Airlines till it collapses. Boycott fully."

There were also some moderate voices such as user Qiuwen in America who urged calm.

United CEO: This is an upsetting event to all of us here at United

"If I were the passenger, I wouldn't want to change my flight too, but can only acknowledge my own bad luck if picked randomly. I would also ask if I was discriminated against if I were picked, but I can complain after the incident. The truth is that when you buy an air ticket, you sign into an agreement and should follow the crew's instruction to be moved."

Expert: United Airlines will be the 'brunt of jokes'

United Airlines is facing a public relations crisis after a video posted to Facebook Sunday showed three security approaching a man who was already seated, asking him to give up his spot on the plane. After the man refused, he was dragged by his arms and screaming toward the front of the plane.

United Continental Chief Executive Oscar Munoz issued a statement Monday afternoon, saying: "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."

On Monday evening, Munoz said in a letter to employees obtained by CNBC that employees "followed established procedures" when removing a passenger from a plane because it was overbooked, and calling the passenger "disruptive and belligerent."

Former Continental CEO: Denied boarding usually handled with more maturity

CNBC's Lauren Thomas and Matt Rosoff contributed to this article.

Follow CNBC International on Twitter and Facebook.