Armed robbers have raided the same bookmakers twice in less than a week.

Thieves first struck at William Hill in Denny, Stirlingshire, at around 9pm on Friday, April 7.

A man wearing a scarf over his face threatened staff with a knife before stealing cash.

Five days later, on April 12, two men entered the shop wearing builder's clothes and threatened a member of staff and two customers with knives.

Nobody was injured but they also escaped with cash.

Police believe the two robberies are linked, although a separate incident at a Ladbrokes in Denny on April 8 is thought to be unconnected.

Detective Inspector Jim Thomson, of Falkirk CID, said: "This was a violent and callous incident which has left the three victims badly upset.

"This also follows a previous robbery at this bookkeepers last Friday, which we are still investigating and believe to be linked to this most recent incident.

"I would ask anyone who was in the Stirling Street area around 7.45pm on Wednesday and has any information that can assist officers to get in touch with us immediately."

The two men reportedly involved in the latest robbery were both white with medium builds.

One was around 6ft with a light tan and a local accent. He wore a yellow high-visibility jacket with a hood up, a white hard hat and dark trousers.

He had pulled a dark scarf over his face.

The other man was around 5ft 9in and wore a yellow high-visibility jacket with a dark blue hard hat and light trousers. He was also wearing a dark scarf over his face.