A spate of cyber-attacks hit supermarket chains across at least 10 European countries on Monday, prompting European Union (EU) officials to warn of a deliberate attempt to disrupt the food supply chain.

Supermarkets reported problems in Belgium, Estonia, Finland, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Germany and Sweden, and the rise in freezer temperatures, reportedly as high as 50°C, forced retailers to discard food. The EU’s food and agriculture commissioner, Christophe Hansen, said the bloc was taking the incidents very seriously and warned of further disruption in the future. In Belgium, dozens of stores reported refrigeration failures and federal prosecutors opened an investigation.