WARSAW, Poland – A Russian citizen suspected of flying a drone over Polish government buildings has been detained for questioning, Polish security officials said Monday.

Warsaw police spokesman Mariusz Mrozek said the man was detained on allegations he violated Poland’s law that bans flying drones in cities and near airports without permission, for safety reasons. If convicted, he could face up to five years in prison.

Natalia Markiewicz, spokeswoman for the Government Protection Office, or BOR, said an officer on duty spotted the drone flying in area guarded by BOR around Prime Minister Beata Szydlo’s office and the nearby Defence Ministry and Belweder Palace, an office of President Andrzej Duda.

BOR officers located the drone’s operator and another Russian citizen in a Porsche car parked near Szydlo’s office, asked him to land the drone safely and notified police, she said.

An Associated Press photographer saw a Porsche car with Moscow registration plates parked near Szydlo’s office and then being driven away under police escort. Warsaw police said the operator’s car was put in a guarded police car park.

Warsaw’s ties with Moscow are tense, especially over Russia’s annexation of Crimea and support for separatists in Ukraine.