A Hunstanton shop assistant was threatened with a knife during an attempted robbery.
In an appeal for witnesses, police said the man threatened a shop worker at the York Avenue Convenience Store and demanded money at around 5pm on January 4.
The female shop assistant refused and the would-be robber fled the scene.
No one was injured and nothing was stolen, a police spokesman said.
The man was wearing a black balaclava, a black waist-length jacket with two thin white reflective stripes on the chest, black trousers and black gloves.
Anyone who witnessed the attempted robbery, or saw a man matching the description running away from the shop, is asked to call police on 101 or Crimestoppers anonymously on 0800 555111.