A man was left with a broken jaw after an unprovoked attack at a Tube station at the weekend.

The 35-year-old victim was topping up his Oyster Card at the ticket machine in Old Street Underground station on Sunday morning at about 9.30am when he was punched in the face and was knocked unconscious.

British Transport Police (BTP) detectives are appealing for information following the shocking attack and have a released an image of a man they want to speak to.

Det Con Oliver Carne, the investigating officer, said: “A man walked over to him [the victim] from behind and punched him in the side of the face.

“He was knocked out and suffered a broken jaw, which requires an operation.”

Det Con Carne continued: “This was a shocking and unprovoked assault that has left the victim needing hospital treatment.

“We don’t tolerate violence on the London Underground network and I’d urge anyone who recognises the man pictured, or has any information that could help our investigation, to please contact us.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting background B5/LUA of 29/10/13. Information can also be passed to the independent charity Crimestoppers, anonymously, on 0800 555 111.