A Ukraine drone attack sparked a fire at an oil depot in the Kamensky district of Russia's southern region of Rostov, its governor said on Wednesday, confirming media reports that several tanks were on fire.

"There are no casualties," the governor, Vasily Golubev, said on the Telegram messaging app. "Firefighters are extinguishing the fire."

Russian air defense units destroyed four drones over the region overnight, the Russian defense ministry said, without mention of an attack on the depot.

Earlier, the Baza Telegram channel, which is close to Russia's security services, said three tanks were burning at the Kamensky oil depot after two drones fell on the area.

Videos posted on Russian social media showed what looked like large tanks ablaze at night. Reuters was able to identify one of the videos as locaed in Rostov's Kamensky district.

There was no immediate comment from Ukraine.

A fuel storage depot in the Kamensky district was attacked in early August as well.

The attack comes while tanks were still on fire at another oil depot in Rostov's Proletarsk district, about 10 days after a Ukrainian attack, Russian Telegram channels said.

Separately, Alexander Gusev, the governor of Voronezh, which borders Ukraine, said debris from a Ukraine-launched drone over the region sparked a fire "near explosive objects." But there was no detonation, he added.

The fire was doused, Gusev said on Telegram, and residents were returning to homes in two settlements from which they had been evacuated.

The Russian defense ministry said eight attack drones were destroyed over the Voronezh region, but gave no details.

Russian officials often do not disclose the full extent of damage inflicted by Ukrainian attacks.

Both sides deny targeting civilians in the 30-month-old war launched by Russia's full-scale invasion of its smaller neighbor. Kyiv says its air attacks aim to destroy energy, transport and military infrastructure key to Moscow's war effort.