A man went in to a Chesterfield post office wielding a knife and demanded money.
Police are appealing for witnesses following the attempted armed robbery at the Holme Hall branch, on Wardgate Way yesterday (September 3).
Staff refused to give him cash and he ran off past Lloyds Pharmacy, the family centre and church and down a footpath in the direction of the school.
He is then believed to have gone onto Loundsley Green Road.
The suspect is described as white, chunky build, wearing a red top and dark bottoms.
Anyone who was in the area and saw a person fitting the description or who has information about the incident should ring 101 and ask for DC Russ Garner or call Crimestoppers anonymously on 0800 555 111.