Iran summoned the French ambassador in Tehran on July 12 to protest a demonstration held in Paris by Iranians in exile who seek the overthrow of the Islamic Republic.
The rally was held on July 9 by the National Council of Resistance of Iran, the political wing of the People's Mujahedin Organization of Iran, a group that waged armed struggle against the Iranian government after the 1979 revolution and assassinated dozens of its top officials.
The group claimed that 100,000 Iranians attended the rally.
"The gathering held by those whose hands are stained by the blood of the Iranian people...is unacceptable," Abolghassem Delfi, director of the West Europe department at Iran's Foreign Ministry, said.
Iranian government spokesman Mohammad Bagher Nobakht described the exiles as an "annihilated terrorist group" and a "stinking corpse," while Foreign Minister Mohammad Javad Zarif called the annual rallies a "political game."
Iranian officials were particularly scornful that the Paris rally was addressed by Prince Turki al-Faisal, former chief of Saudi Arabia's intelligence services, who openly supported the group's struggle against the Iranian government.
Shi'ite Muslim power Iran and Saudi Arabia, bastion of Sunni Islam, are longstanding religious and political rivals.