A man and his four-year-old son were killed in an overnight Russian missile attack near the Ukrainian capital Kyiv, the emergency service said Sunday.

Explosions rang out Saturday night in the centre and east of Kyiv, AFP journalists noted, as Ukraine's air force said two Russian missiles were headed towards the city.

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.

Fragments of a missile fell on residential buildings in Brovary district, neighbouring Kyiv, the State Emergency Service of Ukraine said on Telegram.

A 35-year-old man and his four-year-old son were found dead in the rubble of a building during search and rescue operations, it said. Three other people were seriously injured.

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.

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.