Ukraine’s military said on Thursday that it had struck two more Russian oil depots, pressing ahead with a campaign of attacks against a sector vital for Moscow’s war effort.

The strikes coincide with accelerated lobbying by Ukraine’s political leaders for permission to use weapons supplied by allies in NATO to strike targets deep inside Russia, as Kyiv seeks to bring the pain and hardship of war home to Russia.

The Ukrainian military said it had caused a fire on Wednesday at the Atlas oil depot in the Rostov region, which borders eastern Ukraine. The governor of the region, Vasily Golubev, reported a fire at an oil depot and said that four drones had been shot down.

Ukraine also struck an oil depot in Russia’s Kirov region, which is roughly 800 miles from the Ukrainian border, northeast of Moscow; and an artillery depot in Voronezh region, which borders Ukraine, the general staff said.

The governor of Kirov region, Aleksandr Sokolov, said in a post on Telegram that an oil facility had been set on fire on Wednesday. Two drones were shot down, while three others crashed, he said. The governor of Voronezh region, Aleksandr Gusev, also reported a drone attack, but said in a post on Telegram that no damage was caused.

The Ukrainian claims could not be independently confirmed.

For months, Ukraine has conducted attacks using exploding drones against Russian infrastructure, in particular oil facilities, hoping to slow an offensive by Moscow’s forces. Russia has nevertheless advanced toward the city of Pokrovsk, which is an important transport and logistics hub in eastern Ukraine.