The Russian Defense Ministry said that Ukraine used drones to attack two Russian military airfields on Monday morning.
In a statement carried on the official Russian news agency RIA Novosti, the ministry said the attacks were "in the Saratov and Ryazan regions" but had been intercepted by air defenses.
"On the morning of December 5, the Kiev regime, in order to disable Russian long-range aircraft, attempted to strike with Soviet-made jet unmanned aerial vehicles [drones] at the Diaghilevo military airfields in the Ryazan region and Engels in the Saratov region," the report said.
"The air defense of the Russian Aerospace Forces intercepted these Ukrainian drones flying at low altitude," the Ministry added. "Three Russian soldiers were killed, four more were injured in the attack."
"As a result of the fall and explosion at the Russian airfields of the wreckage of [the] jet drones, the skin of two aircraft was slightly damaged," it said.
Ukraine has not confirmed that it attacked either airfield. Recent satellite imagery shows a substantial number of Russian strategic bombers at the Engels airbase in Saratov.