More than £2,000 was stolen from a woman's bank account after fraudsters placed a skimming device in an Oxford cash machine.

People using the Royal Bank of Scotland machine, outside the Tesco supermarket in Cowley Road, East Oxford, are being warned to be extra vigilant after the woman had between £2,000 and £3,000 taken from her account.

The victim, who did not want to be named but lives in Oxford, used the machine last week.

Although she noticed something unusual flashing on it, she said she did not give it a second thought -- until her bank called her earlier this week.

She was asked if she knew about a series of £400 cash machine withdrawals which been made across the country and discovered a copy of her bank card had been made by a skimming device.

Green councillor Mary-Jane Sareva, who represents the area, said: "It looks as though this machine has been tampered with. "Anyone who has recently used the cash machine outside Tesco needs to check their bank balance and immediately report any odd transactions to the police and their bank.

"We have heard reports of a spate of ATM fraud incidents in the area."

Skimming devices can often be diffcult to spot. They fit into the machine's card slot and can scan and store card details.

A strip of metal containing a hidden pinhole camera is fixed to the top of the machine and films the customer keying in their pin number.

At the time of going to press, Thames Valley Police was unable to confirm details of the incident.

Spokesman Victoria Bartlett said: "Criminals will either use devices to retain cards in machines for retrieval later or use a device to "skim" cards, so a clone can be produced."

She added: "In these cases, legitimate card users may be unaware of the fraud until they actually see their monthly statement."