UK supermarket giant Tesco has restored access to its website and app after an outage struck the service on Saturday, preventing customers from ordering or cancelling deliveries until Sunday evening.

In a statement to The Guardian, Tesco said that "an attempt was made to interfere with our systems, which caused problems with the search function on the site."

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The retailer, whose 1.3 million online orders per week account for nearly 15% of its UK sales, said there was no reason to believe the attempted interference impacted customer data. 

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Tesco confirmed on Sunday evening that its website and app were now restored, but that it was using a virtual waiting room to handle a backlog in orders.  

"Our groceries website and app are back up and running. To help us manage the high volume we're temporarily using a virtual waiting room. We're really sorry for any inconvenience and thank you for your patience," Tesco said on Twitter. 

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