Two projectiles were thrown at the perimeter wall of Russia's consulate in the southern French port city of Marseille on Monday, one of which exploded, a French security source said.
It was not immediately clear if the projectiles cleared the wall. BFM TV said the projectiles were Molotov cocktails and that they landed in the consulate's garden.
Russia demanded a full French investigation and said the incident looked like an act of terrorism, state news agency TASS reported.
No one was injured, the security source said. Consulate staff were kept indoors and police set up a security perimeter around the consulate.
The incident in the southern French city took place on the third anniversary of the Russia-Ukraine war.
"The explosions on the territory of the Russian Consulate General in Marseille have all the hallmarks of a terrorist attack," TASS quoted Russia's Foreign Ministry spokeswoman Maria Zakharova as saying.
