A motorist was the victim of a hit and run robbery as he drove his car through Northampton.
The man was driving along St James Road when a red Renault crashed into his Ford Mondeo at about 0040 GMT on Monday.
A passenger in the Renault then got out the car, assaulted the Mondeo driver and robbed him of a mobile phone.
The passenger and the driver of the Renault then sped off towards Northampton town centre.
Northamptonshire Police said the offender was a white man, between 20 and 22 years old, about 5 ft 8 in tall with a thin build and short black hair.