Russian oil depot on fire after Ukrainian drone attack

"After a drone attack, a fire broke out in a petrol refinery in the Tsimlyansky district," Golubev wrote, adding that there were no casualties.

The area is hundreds of kilometres from the front line.

Russia's defence ministry meanwhile announced that its forces had downed four Ukrainian drones -- two in Rostov, one in the Belgorod region adjoining Ukraine and another in Kursk which is up further north.

Both Moscow and Kyiv have used drones, including larger self-detonating craft with ranges stretching hundreds of kilometres extensively throughout the conflict, which began in February 2022.