According to Russian sources, three soldiers were killed in a drone attack on the Engels-2 military airfield in southern Russia.
"On December 26 at 1:35 Moscow time, Russian anti-aircraft defenses shot down a Ukrainian drone at low altitude while approaching Engels military airfield in the Saratov region," the Russian Defense Ministry said.
Three people were killed by the falling splinters.
The information could not initially be verified independently.
According to media reports, four people were also injured.
"The aircraft technology was not damaged," emphasized the military leadership.
Strategic bombers are stationed at Engels-2, hundreds of kilometers from the Ukrainian border, and Russia uses their missiles to destroy Ukraine's energy infrastructure.
The city on the Volga is more than 500 kilometers from the Ukrainian border.
It is not the first drone attack on the airfield.
According to Russian sources, two planes were damaged in an attack in early December.
At the same time, a military airfield in Ryazan, 200 kilometers south-east of Moscow, was attacked.
The attacks are said to be in response to Russian rocket fire.
In the past, Kyiv has admitted attacks on several air bases on Russia's annexed Crimea peninsula.
It was initially unclear who was behind the recent explosions.
svs/dpa