A computer hacker is reported to have broken into a US grocery store and stolen thousands of individual credit card numbers.

According to Reuters, the hacker targeted two Hannaford Bros stores in New England and Florida, illegally accessing data “during the credit card authorization process”.

4.2 million numbers nicked

Since the attack nearly 2,000 cases of fraud have been detected and linked to the breach. Local Boston radio station WBZ claimed that up to 4.2 million numbers had been stolen. However, it’s believed that the hacker did not manage to steal any personal details.

Hannaford chief executive Ron Hodge has offered his apologies to those customers directly affected by the breach and said that company security was being “aggressively” augmented.

The breach in security is the latest in a series of attacks against major retailers. Another retailer, TJX, recently suffered a similar attack in which up to 46 million numbers were stolen over a period of 18 months, as well as personal information for 451,000 people.