A shopkeeper was threatened by masked robbers wielding what is believed to be a firearm during a raid at a post office.
The two men escaped with a five-figure sum of cash after the robbery at 08:10 in Strathaven, South Lanarkshire.
Police said it had been a “very frightening” experience for the shopkeeper, who was not injured.
Officers are checking CCTV footage and speaking to local businesses and people who were in the area at the time.
Local officers were supported by armed police when they attended the incident, which took place at the post office within the Day to Day store in Green Street.
One of the robbers was about 5ft 10in to 5ft 11in tall, of stocky build, and was wearing blue jeans and black boots.
The other was between 5ft 7in and 5ft 8in tall, of slim build, and was wearing a black cap with an ‘NY’ logo and a jacket with a white zip.
Det Insp Colin Campbell said: “The men, both of whom had their faces covered with masks similar to balaclavas, ran off from the shop via the lane to the side of it.
“At this time they made off on foot. We don’t know if they had access to a vehicle or not, but that will obviously be one of our lines of inquiry.
“It’s possible the suspects had been either hanging about the area prior to the robbery, or indeed over the past few days, so if you did see anyone acting suspiciously, either in a car or not, then please get in touch with police.”