Thieves are using sophisticated equipment to steal bank cards, police warned yesterday.

A number of thefts have occurred over the past two weeks while people have been using outdoor cash machines.

A device, known as the Lebanese Loop, has left five people believing their card had been retained by their bank when, in fact, it had fallen into the hands of the culprits.

The offences occurred in the Hambleton area of North Yorkshire. They were mostly committed out of banking hours so customers were unable to report immediately that the card has been retained in the machine.

Unsure as to whether it is the work of a persistent individual or a number of culprits, North Yorkshire Police have issued a warning for people throughout the North of England to be wary.

DC Kevan Howe, of Northallerton CID, advised that people should examine the slot of the cash machine to make sure the loop is not in place.

Describing the device and how it works, he said: "It tends to be a strip of plastic, shaped like the card-receiving slot on a cash machine. It is backed by a loop made of a thin metal tape."

The offenders are able to use the card with the acquired pin number to withdraw cash from the customers account, usually at a nearby bank.

Anyone whose card is retained and finds such a device is asked to contact the police on (01609) 783131.