A petrol station attendant was left traumatised after two armed robbers threatened her with a meat cleaver and a kitchen knife before stealing £50.
The robbery, at Knowle Garage in Braunton, Devon, happened at 10pm on Saturday.
Devon and Cornwall Police said the balaclava-wearing thieves swung the meat cleaver at the woman.
Officers are appealing for information about the robbery which happened as the garage was about to close.
The men were seen on CCTV entering the store armed with the cleaver and a large kitchen knife, before they threatened the woman and stole around £50 cash from the till.
The knife was described by police as a Kitchen Devil chef's knife with an un-serrated edge and was left at the scene.
A police spokesman said the weapon was about 30cm long with a blade of around 16cm.
Detective Sergeant Paul McWhinnie, of Barnstaple CID, said: "The offenders behaved in a very aggressive and threatening manner, swinging the meat cleaver towards the female member of staff and subjecting her to a very traumatic incident.
"We are appealing for help from the public to try and assist in identifying these offenders.
"We would like to hear from any shopkeepers who believe they may have sold the meat cleaver and Kitchen Devil knife or from anyone who is now missing these items and who suspect a family member or someone they know may be involved in this despicable crime.
"We are also interested in hearing from anyone who believes they may have seen these offenders approaching or leaving the garage and in particular we would like to establish their method of travel to and from the scene."
One of the men was wearing a grey Ultramagnetic brand hooded top and the other had very dark or black clothing and dark trainers with white stripes on the sides, police said.
Anyone with information is asked to contact police on 101 or Crimestoppers on 0800 555111.