Ukrainian long-range offensive drones hit four Russian oil refineries, as well as radar stations and other military targets in Russia, as part of a major attack carried out in the early hours of today, the armed forces of Kiev announced.

Ukraine has dramatically increased its use of drones this year to attack Russian oil facilities, which it sees as legitimate military targets as they feed Russian troops during their nearly 28-month invasion of Ukraine.

“Unmanned aerial vehicles attacked oil refineries in Afipsky, Ilsky, Krasnodar and Astrakhan,” the Ukrainian armed forces said in a statement on the Telegram app.

The Russian armed forces had earlier announced that shot down 70 drones over the Black Sea today and the occupied Ukrainian peninsula of Crimea, 43 drones over Russia’s Krasnodar region and another over Russia’s Volgograd region.

An intelligence source in Kiev told Reuters that the refineries in Afipski, Ilski and Krasnodar produce fuel for Russia’s Black Sea Fleet and that the drone operation targeting them was carried out jointly with the security service SBU.

“Damage to these refineries will significantly complicate the logistics of fueling, making it more costly and time-consuming, as it will have to be done by other refineries,” the source said.

Ukrainian armed forces also said they targeted radar stations and electronic intelligence centers in the Bryansk region and occupied Crimea. The statement does not specify exactly what these centers are.

Warehouses and drone launch facilities, command and control centers in Russia’s Krasnodar region were also hit, according to the same source, which added that explosions and fires were confirmed at those facilities.

The source said the drone strike targeted a training center in the town of Yeysk in the Krasnodar region used by Russia to launch drone strikes against Ukraine.

The Ukrainian armed forces, in their statement, claimed responsibility for the drone attacks carried out against fuel storage facilities in the Russian regions of Tambov and Antigea.

Today’s drone strikes came after Russia carried out the latest in a series of airstrikes against Ukrainian energy facilities, causing blackouts.