"Several drones were detected and destroyed overnight by air defence systems above the Voronezh region," regional governor Alexander Gusev wrote on Telegram.

"Their falling debris set off a fire in a depot" in the Podgorenski district where "explosives began to detonate", Gusev said, adding that there were no indications anybody had been hurt.

Rescue teams were at the scene and Gusev said local people living near the depot were being evacuated.

Russia and Ukraine have used drones, including large explosive devices with a range of hundreds of kilometres (miles), extensively since Russia launched its military operation in February 2022.

Ukraine has stepped up its attacks on Russian territory this year, targeting both energy sites it says supply the Russian army and towns and villages just across the border.