A man was walking along School Lane, Kettering, when a suspect who had been outside the Premier shop, asked him for money.
When the victim refused, the offender punched him to the face. A group of other men then joined in, fighting the victim to the ground. They searched his pockets and stole cash and a prepaid MasterCard.
The incident happened sometime between 12.30am and 1.30am on Saturday, 31 December.
The first offender is described as white, between 20 -25 years of age, around 5ft 7ins tall and with short blonde hair. He was of thin build and wearing a full grey tracksuit.
The other four offenders were men.
Anyone with information can contact Northamptonshire Police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.
Incident Number: 16000438032