Two masked men armed with knifes are believed to have robbed two shops in the Gleadless and Wincobank areas of Sheffield in one hour.
At around 8.15pm Friday 15 January 15 two masked men, one wesring a skeleton novelty mask threatened staff at the Premier Store in Leighton Road, Gleadless, with knives.
Employees sounded the alarm and the two men left the store empty-handed.
Just over 30 minutes later, at around 8.50pm, two masked men entered the Costcutters in Fife Street, Wincobank, and also threatened staff with knives.
A sum of money was taken during this incident.
Officers believe the robberies are linked and are appealing for information following the robberies.
Detective Constable Mike Jenkins from the Force Crime Unit said: “Given the similarities between both reports, we believe these robberies are linked and we are keen to hear from anyone with information about these two individuals.
“The staff involved have been left shaken and distressed, so it is imperative we identify those involved to prevent further incidents of this nature.
“We are working closely with the local communities and reviewing CCTV footage, so if you have any information you think might help our investigation, please get in touch.”
One suspect is described as being around 5ft 8ins tall and was wearing a dark blue hooded jacket with a black balaclava, dark trousers and dark shoes.
The second suspect is described as being around 5ft 9ins tall, of stocky build. He was reportedly wearing a dark blue hooded jacket with a skeleton-type novelty mask, dark trousers and light-coloured shoes.
If you can help officers, please call the Force Crime Unit via 101 quoting incident number 1010 of 15 January 2016. Alternatively, you can call Crimestoppers anonymously on 0800 555 111.