Two betting shops were targeted on the same night by armed raiders carrying guns and knives.
The Coral on Halifax Road, Birley Carr, and Ladbrokes on Jeffcock Road in High Green, were robbed within half an hour of each other.
Three men entered the Coral at around 7.40pm last Wednesday, April 3 and threatened staff with weapons believed to be a firearm, a knife and a spade.
They stole cash from the safe and tills and left in a silver Volkswagen Golf, which sped off and turned into Avisford Road.
Then later, at 9.10pm, on Jeffcock Road, three men entered Ladbrokes and threatened staff with a firearm.
Money was taken from the tills and the robbers left in a silver car.
There were no injuries sustained by anyone in either incident.
Det Con Thomas Ryan from South Yorkshire Police said he could not confirm the two raids were carried out by the same gang.
“At this stage we do not know if the two incidents were carried out by the same people,” he said.
“CCTV footage appears to show the masked men wearing different clothes in each raid and driving a different car, although it is possible they changed clothes and the vehicle in between the two incidents.”
He confirmed police have not yet made any arrests but are appealing for help from the public.
“Thankfully these incidents are rare and we are asking for the community to help us find the people who did this.”
Anyone with information should call 101, quoting incident numbers 1,003 or 1,126 of April 3.