France on Tuesday accused Iran’s intelligence services of planning an attack on an exiled Opposition group near Paris in June, AFP reported.

The French government said it would freeze the assets of two suspected Iranian intelligence operatives named Assadollah Asadi and Saeid Hashemi Moghadam as well as a unit within Tehran’s intelligence services.

Unidentified German officials told the news agency that Asadi, who is a diplomat, has been arrested and will soon be extradited to Belgium, where the alleged plot was discovered in June. Then, the Belgian authorities had arrested a couple who were allegedly preparing to drive into France with a car packed with explosives to a rally of the People’s Mujahedeen of Iran. Six people were later detained in raids coordinated by European police.

“An attempted attack in Villepinte was foiled on June 30,” the French interior, finance and foreign ministries said in a joint statement. “An incident of such gravity on our national territory could not go unpunished.”

After the arrests in June, Iran denied its involvement in the alleged plot. It refuted the allegations again on Tuesday. “We deny the accusations and forcefully condemn the Iranian diplomat’s arrest, and call for his immediate release,” Tehran said in a statement.