Police are appealing for witnesses after a robbery at Whitburn Post Office in South Tyneside.
Officers were called at around 11.30am to reports that a man was armed with what is believed to be a firearm at the shop at North Guards.
It's not known whether it was real or imitation at this stage.
There were no injuries but staff were left shaken by the incident.
Ch Insp Michael Barton, South Tyneside Area Command, said: "This was obviously distressing for those in the shop but I'd like to reassure people that an active investigation is ongoing to trace the man involved."
Anyone with information should contact police on 101 or Crimestoppers, anonymously, on 0800 555 111.