Police in Kent are trying to trace two men in connection with a spate of "Lebanese loop" crimes in the Thanet area.
The loop is attached to the card slot
The offences see a loop device - which police call a Lebanese loop - inserted into a bank's automatic cash machine which prevent the card being returned.
The person who has fitted the loop can then retrieve the card and illegally use it to withdraw money.
In the latest incident in west Kent a woman had £250 taken from her account after her card became stuck in a cash machine outside a supermarket.
She told police she had seen two men "hanging around" while she used the machine at Sainsbury's in Westwood on Monday afternoon.
The men are described as white and in their early-to-mid 30s.
Check card slot for obstructions
Keep your PIN secret
Use cash machines during the day
One was about 5 ft 11 in, with short dark hair and stubble, while the other was about 5 ft 6 in with cropped dark brown hair and was wearing a dark jacket, beige trousers and a beige woolly hat. They drove off in a green car.
Kent Police have issued a warning for people using cash machines.
A statement said: "Before inserting your card, run your finger along the slot. If you feel any obstructions don't use the machine.
"Don't ever let anyone see your personal identification number and where possible use cash machines during the day.
"That way you can go straight into the bank or building society and notify them immediately of any problems."