Potential drone attacks on key energy infrastructure are a serious threat to Russia's energy security, Energy Minister Nikolai Shulginov said on Tuesday. Shulginov did not mention Ukraine by name, but Russia says it has thwarted a series of attempted attacks by Ukrainian drones in recent months.

Ukraine has not publicly acknowledged the attacks on targets in Russia, but senior officials in Kiev occasionally welcome news of successful drone strikes on Russian territory. "The key threat now is acts of illegal interference using drones," Shulginov said during a roundtable discussion on the security of Russia's energy facilities.

He said he was cooperating with the Russian Defense Ministry and the FSB security service on the matter. Russia has previously announced drone strikes in several towns and villages, some of which are hundreds of kilometers from the border with Ukraine.

On Sunday, the Russian Defense Ministry said it foiled a drone attack in a city 220 kilometers south of Moscow, shooting down the drone over residential buildings in the city of Kirevsk.

Russia has accused Ukraine of drone attacks on air bases deep inside Russian territory in December, including a major strategic bomber base near the city of Saratov, after missiles flew hundreds of kilometers through Russian airspace.

Russia has single-handedly launched waves of missile and drone attacks on Ukraine's energy infrastructure over the last six months of the conflict, often cutting power to millions of civilians across Ukraine.