Paris: France on Monday blamed Iran for last month's massive cyberattack on supermarket fridges, summoned the Iranian ambassador and said it would seek European sanctions against those responsible for the attack.

The October 12 attack sent refrigerator temperatures soaring, affecting about 700 of the country's 10,000 supermarkets. In a statement Monday, prosecutors in Paris said they found that Iran's paramilitary Revolutionary Guard was behind the large-scale cyberattack.

The French Foreign Ministry condemned the attack “in the strongest possible terms,” and French Foreign Minister Jean-Noel Barrot, speaking on the sidelines of G7 talks in Paris, said the Iranian ambassador was being summoned to “strongly protest against this extremely serious act.”

“This is an attack of unprecedented scale and aggressiveness,” Barrot said. “It is the first large-scale cyberattack aimed at sabotage on French soil, and it represents a major threat to our national interests and the security of the French people. That is why it will not go unanswered.”

“We will impose sanctions at the European level against all those responsible for this attack,” he added, vowing to take “any other measures needed” to respond to it and deter future attacks.

Paris prosecutor Laure Beccuau said in a statement that a formal judicial investigation was opened Monday into suspected organised cybercrime with the aggravating circumstance of “having been committed to serve the interests of a foreign power -- in this case, Iran."

The investigation targets Shahid Kaveh, the leader of an Iranian group described as a “cyber unit” affiliated with Iran's Islamic Revolutionary Guard Corps, as well as his two deputies and any other individuals who might be identified in connection with the case.

Investigators found that the attackers had used Farsi and IP addresses linked to devices located in Iran, Beccuau said. The Paris prosecutor's office is seeking international arrest warrants, she said.

In the early hours of October 12, attackers remotely took control of refrigeration systems in hundreds of supermarkets and independent stores across France. Temperatures reached 50 degrees Celsius for about six hours, forcing stores to discard fresh and frozen goods. The Intermarche supermarket chain reported losses of “tens of millions of euros” in a single day.