Police are hunting this bus passenger, who punched the driver after an early-morning 'Oyster-rage' row in west London.
Officers from the joint Transport for London and Metropolitan Police Service Workplace Violence Unit are appealing for help in identifying a man.
On Saturday July 5 at about 06:30am, the victim, who was driving a route 111 bus in Kingsley Road, Hounslow, was punched by the suspect following an altercation about his Oyster card.
The suspect then made off towards Hounslow East train station.
The driver was taken to West Middlesex hospital and treated for minor facial injuries and discharged the same day.
The suspect is described as a black man of slim build, wearing a dark clothing.
Anyone with information is urged to contact Detective Constable Andy Morland, leading the investigation for the Workplace Violence Unit on 0777 503 0912 or Crimestoppers anonymously on 0800 555 111.