Two power substations, an oil depot and one person were killed after Ukraine launched drone attacks in several regions on Tuesday, Russian officials reported.

The attacks come after Russia bombed the main children's clinic in Kyiv in broad daylight with a rocket on Monday, and then rained down missiles across Ukraine killing at least 40 civilians.

The Russian Defence Ministry said that its air defence system destroyed 38 drones. This included 21 drones over Rostov, a southern region, and seven others over Kursk. Both of these areas border Ukraine.

It was not immediately known how many drones Ukraine had launched.

Baza Telegram, which has Russian law enforcement sources, reported that explosions were heard near the town of Kalach-on-the-Don, in Russia's southern region Volgograd.

In a Telegram message, Regional Governor Andrei Bocharov stated that drones destroyed by Russian Air Defence Systems had dropped debris which ignited a substation of power and an oil storage depot.

Bocharov reported that the sub-station was quickly extinguished, but the firefighters are still fighting the fire in the oil depot.

He said that the attack had not resulted in any injuries, and added, "There's no danger to residential buildings."

Volgograd was not listed by the Russian Ministry of Defence as a region where drones launched from Ukraine were destroyed.

Vyacheslav Gladkov, the region's governor, said that a man was killed, two others were injured, and several homes were damaged in Belgorod, a bordering region of Ukraine.

The Russian Defence Ministry reported that three drones were destroyed in the Belgorod area. Gladkov reported that four people were killed and 20 injured in the Ukraine attacks of the last day.

Vasily Golubev said that the fire at a substation of a Russian power company in Rostov had been put out overnight after Ukraine launched "tens of drones".

Defence ministry reported that five drones launched from Ukraine were destroyed in the Astrakhan area and two others over Voronezh, a region located several hundred kilometers south of Moscow. However, there was no information on the damage.

Russian officials rarely reveal the full extent to which Ukrainian attacks have caused damage.

The Russian reports could not be independently verified. Ukraine has not yet responded.

Volodymyr Zelenskiy, Ukraine's president, had promised on Monday that Kyiv will retaliate against the missile attack at the children's clinic. (Reporting and editing by Michael Perry in Melbourne, Clarence Fernandez, and Lidia Kelly)