Dozens of supermarkets across seven European countries have been hit by a cyber-attack affecting their refrigerators and freezers.
Around 40 Delhaize supermarkets in Belgium and Luxembourg were affected, while a smaller number of shops were hit in Sweden, Ireland, the Netherlands, Estonia and Finland.
Sabcobel, a Belgian company that manufactures some of the affected refrigerators, said the units' evaporators were switched to defrost mode, causing them to warm up, in what is believed to be the same method used in last month's incident that hit hundreds of French supermarkets.
Millions of euros worth of food had to be thrown away in October, local media reported at the time.
It is unclear who is behind the latest apparent attack.
In the US, authorities are investigating what caused refrigeration malfunctions at a number of American military bases in August and working together with French officials to examine whether the incidents could be linked.
Both Belgium and Sweden's national cyber-security agencies said they were monitoring the incident.
The UK's National Cyber Security Centre said it was working with international partners and industry to "fully understand details of an incident". No incidents have been reported in the UK.
In Flanders, northern Belgium, a Delhaize branch in Hoeilaart told news website Het Laatste Nieuws it had lost €100,000 (£83,500) worth of produce.
The manager said that estimate did not even take into account further losses that would result from closing the shop.
