Moscow says three people have been killed in a Ukrainian drone attack on the Engels bomber base in southern Russia.
Air defenses reportedly shot down the drone, but the falling debris caused casualties in the late-night attack.
Russia has accused Ukraine of carrying out a similar attack on December 5 at an airport home to strategic bombers. The base is located about 500 km (310 mi) northeast of the Ukrainian border.
The Ukrainian military has not officially commented on the attacks.
Russia’s Defense Ministry says its air defenses shot down a low-flying Ukrainian drone at around 01:35 local time on Monday (22:35 GMT Sunday).
It added that three Russian soldiers died of injuries from drone debris.
Earlier, social media users posted videos where sounds like explosions and air sirens could be heard at Engels Airfield.
The governor of the Saratov region said there was no danger to the residents of the town of Engels itself.
Moscow said at the time that in a previous alleged attack on the airport and another airport in the Ryazan region on December 5, three soldiers were also killed by debris from a downed Ukrainian drone. Two planes were slightly damaged.
The Ukrainian military has not commented on the attacks.
Engels Air Base has been repeatedly used by Russia to launch missile attacks on various targets in Ukraine since Moscow launched an all-out offensive on February 24.
The Kremlin has accused Ukraine of invading its territory before, but the alleged attacks in December cut deeper into Russia than previous attacks.
A number of military experts in Ukraine and the West have described the alleged attacks as embarrassing for the Russian army.
