Image copyright Josh Williams Image caption Customers have been left at the tills whilst Asda tries to fix the problem

Asda has apologised after a problem with its card payments system left its customers facing long waits to pay.

The breakdown on Sunday affected stores throughout the UK, most of which have now closed for the day.

Shoppers used social media to criticise the firm and ask for more information as they waited at checkouts.

The company earlier tweeted that the majority of its stores were "back up and working" but advised customers to check if this applied to their branch.

All of the chain's stores were affected by the fault at some point on Sunday but the issue has been resolved at some branches more quickly than others, a spokeswoman said.

'People were shouting'

Becky White had an extra 45 minutes added to her shop in Norwich because of the broken system.

"The doors are shut and people were shouting outside," she told the BBC. "The car park is rammed."

Image copyright @beckywhite__ Image caption Customer Becky White said she had to wait an extra 45 minutes to get out of the shop

Josh Williams was also stuck at the tills at his local Asda in Reading, Berkshire.

"We were waiting for about 50 minutes," he said. "People weren't too pleased! Now we have been told to leave because they can't fix the system."

Others went on to social media to vent their frustration.

Jim Bentley tweeted: "No backup, no redundancy system. We're just stood here like cattle waiting for your systems to start working again. On Sunday."

Shopper Carey Luke said there were issues with telling customers about the problems, tweeting: "I understand these things happen but no one can hear announcements so your in a queue for a till (30 deep) for baskets and then being told."

Image copyright @misitt2000

Image copyright @MrJimBentley

Image copyright @peterlarlewis

Image copyright @Stacy_Lead

Image copyright @Kim_C_Cooper

A spokeswoman for Asda said: "We are in the process of resolving a technical issue with our card payment system in stores.

"We're continuing to process payments as quickly as we can but apologise to our customers for the inconvenience this has caused."