Detective Inspector Louise Ludwig said: "We would urge all shoppers to be wary of anyone who might be watching you at the checkout.
"Always cover your PIN when you enter it into a cash machine or Chip & PIN machine at the tills.
"Try to avoid being distracted by people asking for directions, and keep your valuables safe."
More top news
Thursday night's weather for the east of the region
Thursday night's weather for the west of the region
Simon's Blog - Trees That Look Like Other Things