Dozens of supermarket refrigeration systems in Belgium, Sweden, Ireland and Luxembourg were affected overnight into Monday in what retailers and local media described as a suspected cyber-attack or IT incident, with some stores discarding chilled and frozen food^1,2,3.

In Belgium, about 40 Delhaize stores and 15 Carrefour stores were reported affected¹. Ahold Delhaize, Delhaize's parent, said an IT incident hit fridges and freezers in dozens of its stores in Belgium and Luxembourg after cooling temperatures rose, and that it was investigating². Carrefour said it was analysing the incident at 15 Belgian stores¹.

Swedish chains were also hit^1,2. ICA said a small number of stores outside its central network were affected and that it was supporting those shops¹. One ICA store in Sjöbo, southern Sweden, said on social media that refrigerators and freezers had been hacked overnight and set to 50 C (122 F); the shop closed then reopened¹. Coop told the BBC that seven of its 800 Swedish stores were affected and that the situation was contained¹. The Guardian, citing Aftonbladet, put Coop's figure at six stores².

In Ireland, Musgrave, which owns SuperValu, said refrigeration at 13 stores was affected and that fresh produce had to be thrown away³. Musgrave said the incident was limited to a specific model of refrigeration³. As a precaution, chilled and frozen products in those stores were removed from sale, the company said, adding that other products remained available and that customer safety was the priority³.

The Guardian, citing Le Soir, reported that Belgian sites beyond Delhaize included five Spar outlets, Shop & Go convenience stores at Q8 stations, and smaller Proxy Delhaize shops². Sabcobel chief executive Stephan Moelans told Le Soir that technicians were mobilised from 1 a.m. to disconnect affected installations from the grid². Local media cited by the BBC said thousands of euros of food had been discarded¹.

No outlet named a perpetrator^1,2,3. The episode follows a similar October incident in France in which police said hackers seized cooling units at up to hundreds of stores, with temperatures pushed well above 50 C and large food losses, according to the Guardian's account of that earlier case². RTE likewise noted last month's French supermarket cooling attacks³. Ahold Delhaize last month reported a separate cybersecurity incident to Dutch police, the Guardian reported; that earlier report is not the same as Monday's refrigeration incident².

Investigations by the retailers and, in Ireland, with equipment suppliers and cybersecurity specialists, were continuing Monday^1,3.