Supermarket giant Tesco was forced to close 67 stores across the UK today after a system upgrade that took place last night took down its till systems.

"We have had an IT update overnight, which has affected a minority of our stores,” said a Tesco spokesperson. “They have had to reboot the tills in those stores. We have already heard of plenty of instances where stores have rectified the problem and we are very confident it will be cleared up very soon.”

‘Nothing was running at all when I turned up,” one customer told the Daily Mail newspaper. ‘I gave up in the end and went to Asda.”

It has not been revealed which system was being upgraded before the crash occurred.