The governor of Russia's Ryazan region southeast of Moscow said emergency crews were dealing with the aftermath of an air attack early on Friday on the main town in the region, also called Ryazan.
Governor Pavel Malkov, writing on Telegram, said air defence units had destroyed drones in the region.
Unofficial Telegram channels posted videos of what bloggers described as large blazes in the city and said an oil storage are and a power station had been hit.
Reuters could not independently confirm the reports.