A knife was used during a robbery at a service station at Retford, Nottinghamshire, in the early hours of Saturday 19 March.
Nottinghamshire Police were called just before 3.40am to a report of a man threatening staff at the Esso service station in London Road, Retford with a knife.
The man fled in the direction of Holly Road with a quantity of cash. No-one was injured although staff were left shaken by the incident.
The man is described as white, around 6ft tall and was wearing a dark hoodie, grey bottoms, grey trainers and a grey scarf and a hood that covered his face.
Detectives are continuing their enquiries, and anyone who was in either the Holly Road or London Road areas in the early hours of Saturday 19 March is asked to call Nottinghamshire Police on 101 with any information, quoting incident number 131 of 19 March.