A man was approached by a gang and hit on the back of the head before they smashed up his car.
The 22-year-old victim was with two companions when he was approached by a group of about eight men in Harlestone Road, Northampton, at the junction with Quarry Road.
Following an altercation, one of the men hit the victim on the back of the head with what was believed to be a hammer, causing minor injuries.
The offender and the other men then damaged the victim’s car, smashing the front and back windows.
Police have described the man who carried out the assault as Asian, in his mid-20s and wearing a white top and denim jeans.
The men are believed to have got into three vehicles – a red Vauxhall Corsa, a dark-coloured 3 Series BMW and a dark-coloured convertible BMW.
Witnesses to the assault, which happened at about 9pm on Friday, September 2, or anyone with information, are asked to contact Northamptonshire Police on 101. Alternatively, they can call independent charity Crimestoppers on 0800 555111.