WASHINGTON – The Trump administration accused Tehran on Tuesday of plotting a terrorist attack targeting a regime opposition rally in Paris last month.

German authorities detained an Austria-based Iranian based on Sunday on a European warrant, claiming he and a couple in Belgium had planned to bomb a meeting in the French capital of the Mujahedeen-e-Khalq – an Iranian exile organization that advocates the violent overthrow of the Tehran regime. Vienna had lifted the Iranian official’s diplomatic immunity based on intelligence provided by the Belgian authorities. French police also arrested an individual of Iranian origin suspected to be involved in the plot.

Iranian officials dismissed the case as a “false flag” operation, claiming the MEK itself was behind the scheme. The Iranian regime and its supporters claim that the MEK is a terrorist organization conducting covert operations inside Iran. But a senior State Department official said the Trump administration is skeptical.

The US takes the charges “very seriously,” the official told reporters. “We are working very closely with the Belgians, Austrians and Germans to get to the bottom of this plot to conduct a bomb attack in Paris that had two Americans speaking, attending.”

Asked if the administration believes Iran is responsible, the official responded, “Yes, we do.”

State Department officials met with their peers in Austria, Saudi Arabia and Belgium this week to discuss ways to further pressure Iran economically, in light of President Donald Trump’s withdrawal from an international nuclear deal in May.

The Paris plot, the official said, “exemplifies” the danger of Iran’s government.

“We had an Iranian diplomat out of the Austrian embassy as part of the plot to bomb a meeting of Iranian opposition leaders in Paris,” the official said. “And the United States is urging all nations to carefully examine diplomats in Iranian embassies to ensure their countries’ own security.”

“If Iran can plot bomb attacks in Paris, they can plot attacks anywhere in the world,” the official said, “and we urge all nations to be vigilant about Iran using embassies as diplomatic cover to plot terrorist attacks.”