Police Scotland is urging the public to be vigilant after skimming devices were reported on cash machines in the Beauly and Nairn areas.
Both incidents involved a device being fitted to the ATMs which "captured" the bank card of anyone who used it and refused to return the card after an attempted transaction.
Cameras were also fitted to film the user entering the PIN code for the stolen card.
Two men - aged 24 and 25-years-old - have been arrested in connection with these incidents and are due to appear at Inverness Sheriff Court in due course.
Both the Nairn and Beauly incidents were reported to Police on Friday, July 21.
Police Scotland want to make anybody using a cash machine alert to this particular type of scam and urge anyone who sees anything suspicious around an ATM to report it immediately to Police, as well as the bank or shop where the cash machine is located.
Police Scotland offer the following advice:
• Check the card reader and the front fascia for anything that appears to be out of the ordinary before inserting your card.
• Check for any unusual attachments to the ATM.
• Cover the PIN key pad as you enter your number by obscuring it with your free hand.
• If anything looks out of place, they should not enter their card or PIN number but should immediately inform the authorities.
• If you insert your card, and it appears to be retained or jammed, check the fascia and notify the bank or service provider immediately. Contact the police and service provider immediately should you discover a device attached to an ATM.
• Check your account balance regularly and inform your bank immediately if your account shows any transactions you did not make.
Detective Inspector Richard Baird said: "We do not want to alarm people unduly about the use of cash machines but the public should be alert to this type of activity and take sensible precautions.
"Our enquiries are ongoing in relation to the recent incidents and anybody who has information should get in touch with us as soon as possible.
"Anyone who finds any suspicious device or has any information regarding suspicious activity around cash machines is urged to contact Police Scotland on 101, or Crimestoppers on 0800 555 111."