Cathay Pacific Airways apologised on Tuesday after a passenger accused its flight attendants of mocking non-English speakers in an online post that went viral on Chinese social media.

Cathay said the experience of passengers travelling on a flight from the Chinese city of Chengdu to Hong Kong caused “widespread concern” and said it sincerely apologised.

“We have suspended the flight attendants concerned and launched an internal investigation,” the airline said.

A passenger on the flight wrote in an online post that flight attendants complained among themselves about passengers in English and Cantonese. They said the attendants made fun of others for asking for a carpet instead of a blanket in English.

“If you cannot say blanket in English, you cannot have it … carpet is on the floor, feel free if you want to lie on it,” a flight attendant said according to a recording that was shared widely online. Reuters could not verify the authenticity of the clip.