Shoppers are being urged to be on their guard after a number of thefts in Chesterfield.
The most recent theft happened in the town centre on Friday, when a 52-year-old woman shopping in the High Street and Burlington Street area had her purse stolen.
Her card was later used to withdraw cash.
Officers are investigating 12 similar offences committed in the town centre since September, and three thefts in Chesterfield supermarkets.
Inspector Russell Dakin, of the community safety unit in Chesterfield, said: “It really is important that shoppers remain vigilant, keeping handbags closed and reporting anything suspicious to police or shop staff straight away.
“When paying at the till or using a cash machine, make sure you cover the machine with your hand as you enter your PIN, and if someone asks for help, speaks to you, or uses things like maps to distract you, make sure you keep your handbag and purse close.
“Patrols are being carried out in the town centre and at local stores to help keep local shoppers safe but please do your bit to make sure you don’t become a vulnerable target for thieves.”
n Call Derbyshire police on 101 or Crimestoppers on 0800 555111.