Thames Valley Police is appealing for witnesses following an incident of grievous bodily harm in Milton Keynes.
At around 4.30am on Thursday 27 December the victim, a 40-year-old man who works as a taxi driver, picked up two men from Watling Street in Bletchley.
The victim pulled up in Wallinger Drive, where both men attempted to leave the taxi without paying a fare.
One of the offenders approached the driver side door, removed him from the vehicle and violently assaulted him.
The assault stopped after a vehicle flashed its lights at the offenders, who then walked away.
The victim sustained a fracture to his left eye socket, a grazed knee, and cuts and bruises. He was taken to Milton Keynes University Hospital and has since been discharged.
The first offender is described as white, aged between 25 and 30 years old, of medium build with short light coloured hair. He was dressed in a grey jacket.
The second offender is described as black, aged in his early to mid-twenties, has an athletic build and medium length curly hair. He was dressed in a brown/yellow coloured jumper.
Investigating officer Detective Constable Mandy Banfield, of Milton Keynes Force CID, said: “We are appealing for witnesses to this assault which was a traumatic experience for the victim.
“We are particularly eager to locate the driver of the vehicle which flashed its headlights towards the offenders before they walked away. We would hope this person has information which could help our investigation.
“Anyone with information is urged to get in touch with us as soon as possible.”