Russian forces on Thursday shot down a drone near Engels, a base for Russia's strategic aircraft, located hundreds of kilometres from Ukraine's border, regional authorities said.

Kyiv says Engels, in Russia's central region of Saratov, houses aircraft used to strike Ukraine.

This month the base has already been targeted twice in deadly attacks that Moscow blames on Ukraine.

"The air defence system has been activated in the Engels district," governor Roman Busargin said on social media.

He said a drone had been shot down and no one was injured.

But fragments damaged the fence of a private home, a car and a garage, and shattered the windows of a house balcony, Busargin said.

Russia said on Monday it downed a drone over Engels airfield and that falling debris killed three people.

On December 5, Moscow said Ukraine's Soviet-made drones had attacked that base and another in the Ryazan region, leaving three people dead.

The Engels drone raids are the deepest reported strikes into Russian territory since the start of Moscow's offensive in Ukraine on February 24.