Police in Derry are currently investigating two attempted frauds at local businesses.
A PSNI spokesperson said the frauds were for 'large sums of money'.
The spokesperson said: "Two males are currently being sought by police in relation to this and an investigation is ongoing.
"One male distracts the staff whilst the other takes the card reader and uses it to refund large sums of money on to their cards.
"Please please keep your card readers out of sight of the public. Don't leave them unattended and make sure your CCTV systems are operational.
"Take all steps to protect yourself," added the police spokesperson.
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