Overnight Russian drone attacks sparked a fire in Kyiv and injured a woman and damaged several houses in the northeastern city of Sumy, Ukrainian officials said on Monday.

No injuries were reported in the attack that sparked a fire at a non-residential building in Kyiv, Mayor Vitali Klitschko said in a post on the Telegram messaging app.

But a 38-year-old woman was hospitalised after Russia launched drones at Sumy, which is the administrative centre of the broader Sumy region, Ihor Kalchenko, governor of the region said on Telegram.

Five houses were also damaged, he added.

The full-scale of the Russian overnight attack on Ukraine was not immediately known. There was no comment from Russia.

Both sides deny targeting civilians in the war that Russia started with its full-scale invasion in February 2022. But thousands of civilians have died in the conflict, the vast majority of them Ukrainian.