France has blamed Iranian intelligence services of being behind a foiled bombing plot earlier this year.
It comes after allegations that an alleged attack was planned at a meeting of the Iranian opposition group National Council of Resistance of Iran near Paris on June 30th.
BBC reports that the council is considered a political arm of the Mujahideen-e-Khalq (MEK) - a dissident group which is strongly opposed by authorities in Tehran.
A number of high-profile international figures - including Donald Trump's lawyer Rudy Giuliani - attended the French meeting in June.
It's believed the plot was foiled following the arrest of two people in Belgium in possession of explosives.
Another man was arrested in Paris, while an Austria-based Iranian diplomat - Assadollah Assadi - was detained in Germany.
In a joint statement today, three French ministers said the "extremely serious" alleged plot "could not go unanswered".
As well as blaming Iran's ministry of intelligence, French officials also said that they had frozen assets belonging to two Iranian nationals - Assadollah Asadi, and another individual named Saeid Hashemi Moghadam.
Foreign affairs minister Jean-Yves La Drain observed: "The foiled attack in Villepinte confirms the need for a tough approach in our relations with Iran".
Economy minister Bruno Le Maire added: "We must dry up the financing channels of terrorists in order to put an end to their intolerable acts.
"We are acting firmly at the national level, and we continue to strengthen the arrangements at the international level. "
Iran has denied the allegations, with Iranian state media quoting a foreign ministry spokesperson describing the allegations as "ridiculous" and "unjust".