(Bloomberg) --

Tesco Plc said its online operations have been restored following an attempted hack on its website and app that left customers unable to place orders with Britain’s largest grocer. 

The company first disclosed an issue on Saturday when it said an attempt to interfere with its systems had caused problems with the search function on the website. On Sunday Tesco said web sales had been restored but it was temporarily using a “virtual waiting room” to manage high volumes of demand as it sought to get back to normal. 

Tesco hasn’t disclosed detailed information on the nature of the attack but has said attempts to compromise its systems were made overnight from Friday to Saturday. A spokesperson for the grocer said there’s no reason to believe that the issue impacts customer data and the company is continuing to ensure that all data is safe.

Online sales have become increasingly important for Britain’s grocers since the pandemic as more people are using the internet to order food. Earlier this month Tesco said interim online sales are now up 74% over two years and it has more than 6 million app users. 

Tesco has been hacked before. In 2014 it had to deactivate some customer accounts after fearing login details were compromised and its banking arm has weathered a hack attempt before too. 

Targeted attacks on large corporates globally are becoming increasingly common with a recent hit on Colonial Pipeline Co. in May shutting down the U.S.’s largest fuel pipeline. A cyber attack also forced global meat manufacturer JBS SA to close down all of its beef plants in the U.S., accounting for almost a quarter of American suppliers, earlier this year. 

Tesco shares were little changed at 8:11 a.m. in London.

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