PARIS, Nov. 9 (Xinhua) -- French Foreign Minister Jean-Noel Barrot on Monday said Iran's Islamic Revolution Guard Corps (IRGC) was responsible for the cyberattack targeting refrigeration systems at hundreds of French supermarkets in October, citing the attack pattern of an IRGC affiliate.

Speaking to reporters in Paris after a meeting of Group of Seven (G7) foreign ministers, Barrot said France had summoned the Iranian ambassador to France to lodge a "strong protest" over the attack.

He described the cyberattack as "a major infringement of the nation's interests" and said those responsible would face "sanctions at the European level."

The Paris prosecutor's office has opened a judicial investigation into the cyberattack, French daily Le Monde reported Monday. The investigation targets the leader of Shahid Kaveh, an Iranian cyber offensive unit affiliated with the IRGC's Electronic and Cyber Center, along with two deputies and "any other individuals who may be identified".

The office said investigators, with support from specialized state agencies, had uncovered an attack pattern characteristic of the unit, including "the use of Farsi and IP addresses linked to devices located in Iran."

Iranian authorities have not yet made any official comment in response to France's allegations.

The attack, carried out overnight Oct. 11 to 12, targeted the refrigeration systems of hundreds of French supermarkets. Hackers remotely activated continuous defrost cycles and set the target temperature to 50 degrees Celsius, causing financial losses estimated at several million euros, French news channel BFMTV reported.