A man has undergone surgery after being attacked at a Tube station.

A 31-year-old from Woodford Green had a noxious substance sprayed in his face before being punched and pushed down the stairs at Debden station on Sunday at 9.15pm.

British Transport Police have released CCTV images of two men who they would like to speak to in connection with the assault.

Sergeant Fin Egan, investigating officer, said: “A verbal altercation took place between the victim and a group of men outside the station.

“One of the men then approached the victim inside the station and sprayed a noxious substance in his face, before fleeing when the station supervisor intervened.

“As the victim made his way up the stairs of the footbridge, a second man ran up to him and punched him in the head. The man then pushed the victim down the stairs and ran out of the station.”

The man had to have knee surgery and was left with cuts to his face and head.

DS Egan added: “Violence on the Tube and rail network is completely unacceptable and we will do everything we can to bring offenders to justice.

“I’m urging anyone who recognises the men pictured, or has any information that could assist with the investigation, to please contact us.”

Anyone with information is asked contact British Transport Police on Freefone 0800 40 50 40, or text 61016, quoting incident reference LUA/B6 of 20/02/14.

Alternatively call the independent charity Crimestoppers, anonymously, on 0800 555 111.