The footage showed two IndiGo staff members pinning a passenger to the ground after an argument, as reported by the BBC. The male passenger–identified by the airline as Rajiv Katiyal–shouts and attempts to fight back but is overpowered. It wasn’t clear from the footage what triggered the scuffle, which unfolded on the tarmac of Delhi airport where the plane had just landed.

IndiGo’s management fired the whistleblower who recorded the video, but not the employees responsible for the incident.

IndiGo has taken to Twitter to publicly apologize to Mr Katiyal for the incident.

“Whatever may have been the provocation, our staff were completely out of line and didn’t follow laid down procedures,” said IndiGo president Aditya Ghosh.

While “the main culprit” was said to have been immediately terminated by Mr. Ghosh, it’s not clear which employee he is referring to–the whistleblowing video recorder or those responsible for assaulting the passenger.

IndiGo is a private airline owned by InterGlobe Aviation, and is India’s largest by passengers. The company has been asked to file a report about the incident by India’s aviation authorities. InterGlobe’s stock price fell 2.1% in Mumbai Wednesday.

Airlines’ customer relations practices around the world have increasingly come under the spotlight since David Dao, an Asian-American, was forcefully dragged off a United Airlines flight by airport security staff at the request of the airline’s crew earlier this year.