Russia announced on Monday that its air defenses caught Ukrainian drones over two military airfields in Russia, hundreds of kilometers from the boundary between the two nations.
The falling debris from the autonomous vehicles caused minor damage to two planes, according to a defense ministry statement.
Three Russian servicemen were murdered and four were injured in incidents in the districts of Ryazan and Saratov.
It is suspected that long-range strategic bombers are stationed at the airfields.
Earlier, there were reports of major explosions at the Engels airbase in Saratov and the Dyagilevo airport in Ryazan, but there was no official explanation for their cause.
Hours later, Russia unleashed a barrage of missiles toward Ukrainian targets, although Kyiv claims to have destroyed most of them.
Ukraine has not made an official statement regarding the blasts. However, its air force tweeted “what happened?” along with photographs of what appeared to be a severely damaged aircraft and a partying face emoji.
Moscow has previously accused Ukraine of invading its territory, but these claimed incursions are more extensive than earlier ones. Ukrainian strikes thus far into Russia will disgrace the Kremlin, according to Steve Rosenberg, the BBC’s Russia editor.
Sunday’s satellite photographs appeared to reveal a big fleet of Russian heavy bombers stationed at the Engels airport.
They depict what appear to be strategic bombers of the Tu-160 and Tu-95 types, which are capable of firing cruise missiles – one of the weapons employed in the Ukraine attacks.
Other satellite photographs released the previous week appeared to reveal an increase in the number of military aircraft at the same airbase.
According to Kremlin spokesman Dmitry Peskov, Russian President Vladimir Putin has been notified of the two occurrences.