Debris from a destroyed drone sparked a fire at an industrial facility in Kstovo, in Nizhny Novgorod, governor of the region that lies east of Moscow said on the Telegram messaging app.

"According to preliminary data, there are no casualties," Gleb Nikitin, the governor, said.

He did not disclose further detail. Baza, a Russian Telegram news channel, which is close to Russia's security services, reported that an oil refinery in Kstovo was on fire.

In the western Russia region of Smolensk, which borders Belarus, air defence systems destroyed a drone attempting to attack a nuclear power facility, Governor Vasily Anokhin said. He added that parts of the region were under a "massive" drone attack.

"According to preliminary information, one of the drones was shot down during an attempt to attack a nuclear power facility," Anokhin said on the Telegram messaging app. "There were no casualties or damage."

Another 26 drones were downed over the Bryansk region that borders Ukraine, and 20 drones over the Tver region that borders the Moscow region to its south, regional governors said. There were no damage or casualties, they said.

Russian aviation watchdog Rosaviatsia said on Telegram that in order to ensure safety it was halting all flights at the Kazan airport. Kazan, the capital of the Republic of Tatarstan, lies some 830 km (516 miles) east of Moscow.

The full scale of attacks was not immediately known. Reuters could not independently verify the reports and there was no comment from Ukraine.

Both sides deny targeting civilians in their attacks in the war that Russia started with a full-scale invasion in February 2022. Kyiv says that its attacks inside Russia aim to destroy infrastructure key to Moscow's war efforts.