France decided to seize the assets, due to links between the Iranian intelligence services and a foiled attack against an Iranian opposition rally near Paris on June 30.
"An attempted attack in Villepinte was foiled on June 30. An incident of such gravity on our national territory could not go unpunished," a joint statement issued by the French Foreign Ministry, the French Interior Ministry and the French Economy Ministry said.
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French authorities were referring to the case that emerged earlier this summer, when several individuals, including Assadi, a diplomat from the Iranian Embassy in Vienna, were detained in France, Germany and Belgium as part of a Brussels-led probe into a foiled bomb attack plot in the Parisian suburb of Villepinte.