France summoned the Iranian ambassador on Tuesday after accusing Tehran of being behind a cyber attack that disrupted cooling systems in hundreds of major stores. French Foreign Minister Jean-Noël Barrot warned that Paris could respond by taking cyber measures of its own.
French officials accused Iran's Revolutionary Guard on Monday of being responsible for the attacks, which disrupted cooling systems in shops across France in October.
The Ministry of Foreign Affairs said in a statement: "The summoning of the Iranian ambassador, announced by the minister yesterday, took place this morning."
Barrot told France Info television that France would seek to impose European Union sanctions in response to what he described as an unprecedented attack "in terms of scope and aggression on our country."
He suggested that further measures could also be taken but would not be disclosed publicly.
"We will take all necessary measures, including steps we will not discuss publicly, if we see that they are appropriate and necessary to counter any new attacks and punish those responsible for this unacceptable aggression," he added.
Barrot said France's cyber defense doctrine gives authorities a range of options.
Iran, meanwhile, rejected France's accusations as "baseless." The Iranian Foreign Ministry said in a statement that it "categorically rejects the French government's baseless and biased accusations against Iran regarding alleged cyber activities in France," adding that it "strongly condemns this cheap policy of leveling accusations against the Islamic Republic."
The hacks targeting hundreds of major stores in early October were among the most disruptive cyber attacks since the outbreak of Iran's war in February, a conflict marked by scattered incidents suspected to involve digital sabotage.
Other incidents included hacks targeting the transportation system in Los Angeles in March and water treatment plants in the United States in May.
Relations between Paris and Tehran have been tense for years over Iran's nuclear and missile programs, its activities in the region, and its detention of several French nationals.
Although relations improved after the release of those detainees and France's distancing itself from the U.S. war on Iran, they deteriorated again during the summer after the Islamic Republic arrested and later expelled French diplomats. Paris responded by expelling Iranian diplomats.
French officials say Tehran has adopted an increasingly hostile approach toward France, particularly because of Paris's support for Iranian civil society.
