A disc array fault left thousands of Barclays Bank customers unable to access their bank accounts online or withdraw money from cash machines in the south of England for three hours yesterday.

Customers in the south of England were completely unable to withdraw their money from cash machines yesterday between 1-4pm, a peak period, when around 1500 of its 3500 ATMs across the UK went down.

The problem also prevented customers from accessing their online or telephone banking service, if they are registered at banks in the south of England.

Barclays uses Hitachi Data Systems storage disc arrays, back office systems linked into the ATM cash machines, at its service centre in Gloucester. But neither Barclays nor HDS could confirm what technology was affected, and the bank is understood to be analysing the problem.

But neither Barclays nor HDS could confirm what technology was affected, and the bank is understood to be analysing the problem.

The high street bank was unable to comment, at the time of writing, on what business continuity and backup systems it has in place.

Customers reacted angrily, posting comments on the web. One wrote on Twitter: “As the bank crashed, I found myself in a mess with most of England - where is our apology?”

Another said that Barclays had lost a £70,000 payment from his company.

All the machines are now working, according to a spokesperson at Barclays, after the faulty hardware was replaced at 4pm.

The spokesperson apologised for the problem and said:"The main impact was to our telephone and online banking services which were temporarily unable to process transactions or access customer accounts.”

The staff in bank branches were still able to provide cash withdrawals, the bank said.

Barclays has had other serious problems with customer account systems in recent months. Last October, its website malfunctioned twice in a fortnight, leaving customers unable to login and access their accounts.

The migration of 1.7 million Goldfish customers onto Barclaycard’s services, after the bank purchased the credit card business a year ago February, may have been part of that problem, it is understood. Barclaycard is said to be experiencing significantly higher volumes of customers each day trying to access their accounts online.

It is not known if the problem with cash machines yesterday is linked to last October's website malfunctions.