Ukraine claims to have attacked a military depot in Russian Voronezh.
The statement from Kiev comes after the governor of the Russian border region earlier reported explosions.
Videos published in Russian state media show a fire raging to the sound of several loud explosions.
Earlier in the morning, the Defence Ministry in Moscow claimed that at least one drone fired from Ukraine was shot down by Russian air defence over Voronezh during the night.
Additionally, nearly 30 drones were said to have been shot down over Belgorod, also a Russian region bordering Ukraine. Governor Vyacheslav Gladkov claims in a video published on Telegram that several people were injured and an elderly woman was found dead after an attack – although it is unclear when.
Russian reports of Ukrainian attacks are generally difficult to verify. Russia's military command at the federal level tends to give a false or exaggerated picture of the war's development.
Ukraine has, however, taken responsibility for an increasing number of attacks targeting Russian energy and military facilities, particularly since Kiev received the green light from several countries to direct donated weapons against Russian territory.