Machete-wielding robbers stole cash from two borough betting shops last weekend.
Police have launched an investigation after the Betfred stores were targeted last weekend.
The first robbery, which happened at around 7.30pm on Saturday October 28, saw two men enter Betfred on Mesnes Street.
One of the men jumped over the counter while the other stood near to the door holding a machete.
Just 25 minutes later at 7.55pm, three men entered Betfred on Walthew Lane in Platt Bridge.
Two of the men jumped over the counter and made demands for cash while the other again stood near to the door holding a machete.
In both robberies, the group fled the shop with a large quantity of cash in an unknown direction.
All three men are described as wearing dark clothing with hoods up and having their faces fully or partially covered.
The man carrying the machete is described as wearing a black Nike hooded top with a white trim and dark tracksuit bottoms.
Detective Constable Andy Partington of GMP’s Wigan Borough, said: “The circumstances in both of these incidents are so similar that we are treating them as linked and are determined that the approach they are taking will be put to an end.
“These people carried out these frightening robberies with no thought for the wellbeing or safety of those working at the time - people who were simply earning an honest living.
“I’m urging anyone who saw anything of this nature at the time to get in touch with us - just think of how terrified the shop workers were - we need to get justice for them.”
Anyone with information should contact police on 0161 856 7225 or the independent charity Crimestoppers, anonymously, on 0800 555 111.