Dozens of supermarkets in Belgium and Sweden have been hit by a suspected cyber-attack affecting its refrigerators and freezers.

Around 40 Delhaize supermarkets in Belgium and Luxembourg were affected, while several ICA and Coop shops in Sweden were hit. Thirteen SuperValu shops have also been impacted in Ireland.

Millions of euros worth of food has had to be thrown away, according to local media reports, with one ICA store in Sweden saying temperatures for its freezers had been set to 50 C (122F).

It is not clear who is behind the attack, which follows a similar incident last month that affected hundreds of French supermarkets.