Hackers have forced the temperature of many French supermarket fridges up to 50C overnight, in an “unprecedented” cyber-attack affecting several hundred stores across the country, with fires and food losses reported.

The Paris prosecutor’s office said on Monday ⁠the large-scale attack was “affecting connected refrigerators ⁠in several ​major food retailers across France”. Reported damage included “food losses and fires”, it added.

The prime minister, Sébastien Lecornu, instructed France’s national cybersecurity agency ANSSI to investigate, ⁠a person in his office said.

France “was coordinating with its European counterparts, as other countries may also be affected”, while also investigating whether any other French ⁠firms were at risk, they said.