Multiple police units were called to a shop in Norwich after reports of a man with a gun yesterday afternoon.
He entered the store on Plumstead Road East just before 1.20pm, wielding a BB gun.
The suspect left Fish's newsagents without taking anything, and nobody was injured during the incident.
The robber was wearing a motorcycle helmet.
He fled the scene towards Woodside road near the doctors surgery.
A police drone, dog units and armed units were called to the scene.
Detective Inspector Chris Burgess, from Norwich CID, said: "Officers are continuing to examine CCTV from the shop and surrounding area.
"I would appeal to anyone who witnessed the incident or may have seen a man acting suspiciously to come forward".
Norfolk Constabulary have asked anyone who saw what happened to contact Norwich CID on 101, or call Crimestoppers anonymously on 0800 555 111.