A 24-year-old man was held by the throat and punched in the face several times during a robbery in Kingsthorpe, Northampton.
The victim had been to the Co-op in Newnham Road and was walking along Brockhall Road, when he was stopped by three men who came out of an alleyway.
One of the men held the victim by the throat while the other two men searched him, stealing cash, bank cards and a mobile phone.
The robbers then demanded the victim tell them his PIN and punched him several times in the face before running off.
The robbery happened on Thursday, August 21, between 9.45pm and 10.10pm.
The robbers are described as between 5ft 6in and 5ft 8in, with a medium build. They were wearing dark clothing, gloves and had hoods up.
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101. Alternatively, they can call Crimestoppers on 0800 555111.
Officers would particularly like to speak to a man believed to have been parked in a vehicle a few metres from where the offence took place and who may have witnessed the incident.