Air raid sirens sounded in the capital and at least two flashes could be seen against the night sky, said an AFP reporter.

Kyiv's military administration said in a post on Telegram that the city's air defence systems had been activated. Ukraine's air force said five other regions were being attacked by drones.

There has been growing concern among many Ukrainians in recent days that Moscow might launch air raids in response to Kyiv's recent offensive inside Russian territory.

Ukrainian officials have not so far given any details on possible casualties or damage.

Ukraine has been regularly hit by deadly Russian air strikes from missiles and drones.

Kyiv has repeatedly called for its allies in the West to provide it with more air-defence systems.

On the Russian side, Kursk regional governor Alexei Smirnov said 13 people had been injured in Kursk city, including two seriously, when debris from a downed Ukrainian missile fell on a building during the night.