A hooded attacker held a man against a wall with a knife to his throat outside a store in Northampton.
Police are appealing for witnesses to the attempted robbery in Chalcombe Avenue, Kingsthorpe, just after 11pm on Wednesday, March 30.
The victim had just got off a bus outside the Nisa store and was going up the steps to the side of the shop when another man pushed him against a wall and held a knife to his throat, demanding he hand over his bag.
Somebody passing in a vehicle then stopped and asked if he was okay, at which point the offender ran off down Chalcombe Avenue towards Harborough Road.
The offender was described as white, tall, about 40-years-old with an English accent. He was wearing a dark- blue hoodie with the hood up and white trainers.
Police would like to hear from the witness who stopped their car to help the victim.
Witnesses, or anyone with information, are asked to contact Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.