Videos posted online showed a man, who appears to be Asian, being forcibly dragged from his window seat by security officers.
An eyewitness said the man was a “Chinese American doctor” who would not give up his seat, US media reported. The man has not yet been identified.
United Airlines issued an official apology after the incident.
A video taken by Audra Bridges who was on board the flight from Chicago to Louisville, the visibly distressed man was seen being hauled out of his seat. The video has been shared millions of times and photos of his bloodied face also spread quickly.
Source: BBC News Online