Fatal Ukrainian drone barrage on Russia hits oil refinery

A Ukrainian drone attack killed a mother and her toddler in western Russia on Wednesday, local officials said, in a major overnight barrage that set an oil refinery ablaze and targeted a nuclear facility.

The Ukrainian attack over swathes of western Russia is just the latest in a series of escalating Russian and Ukrainian aerial strikes, targeting energy and military facilities over the nearly three-year war.

The assaults have ramped up since Donald Trump won last year's US presidential election, with the Republican seeking a swift end to the fighting.

"The most terrible thing happened as a result of a drone attack on a residential house -- a two-year-old child and his mother were killed," Vyacheslav Gladkov, the governor of Russia's Belgorod border region said.

Another child and his father were also injured in the strike, he wrote on social media.

Russia's defence ministry said earlier it had downed 104 Ukrainian drones over western regions including Kursk and Bryansk, with smaller numbers intercepted over Smolensk, Tver, Belgorod and elsewhere.

Ukraine said one strike had hit an oil refinery in the town of Kstovo in Russia's Nizhny Novgorod region, around 800 kilometres (500 miles) from the front lines in eastern Ukraine.

Falling debris from a drone triggered a fire at the site, Russia said earlier.

"As a result of repelling a drone attack, debris fell on the Sibur-Kstovo enterprise causing a fire to break out," Sibur, a large petrochemical firm that owns the facility, said on Telegram.

Both Sibur and the regional governor said there were no casualties and firefighters were working to extinguish the blaze.

Images on social media -- not verified by AFP -- showed a huge blaze illuminating an urban skyline with flames and plumes of smoke rising over buildings.