Europe on alert after supermarket freezers hit by cyber-attacks in nine countries

Mathieu Tilman, a manager at a Delhaize supermarket in Belgium, said he was shocked by this kind of attack: "I don't even understand how anyone could do this... How can we end up throwing away so much food? I find it truly distressing. In moments like these, you just feel like quitting your job."

In Ireland, 13 SuperValu stores were impacted by what the chain's owner, Musgrave Group, called a cyber-incident. "Replenishment of chilled and frozen ranges in the affected stores is well under way," a spokesman said on Monday.

A small number of corner shops in the Netherlands also suffered disruption. Last month, supermarket chain Albert Heijn had to take several services offline because of a separate cyber-attack.