Cash has been stolen during an early-morning raid on a branch of Gregg's in Edinburgh's Boswall Parkway.
Two armed men approached a female assistant as she was opening the shop shortly before 06:00.
After taking money from the premises they ran off in the direction of Crewe Place.
Police have appealed for witnesses, saying the incident had been a "terrifying experience" for the shop assistant.
Officers have also issued a description of the suspects.
The first is described as white, 5ft 10in, early 20s, slight build, wearing dark clothing with the hood up and a black balaclava or a scarf covering the face and wearing gloves and with a local accent.
The second is described as white, early 20s, 5ft 8in, slight build, wearing a red hooded top with the hood up and dark body warmer on top, a scarf over his face up to his nose, and with a local accent.
The vehicle one of them got into is described as a dark hatchback.
Det Con Alison Wyllie of Police Scotland said: "This was a terrifying experience for the female assistant who was opening up the shop alone and in the early hours of the morning.
"We ask that anyone who recognises the description of the suspect or witnessed events unfold, to contact police immediately."