Ukraine's Security Service (SBU) carried out drone strikes early on April 24 that set fire to oil-storage facilities in Russia's Smolensk region, a source familiar with the issue has told RFE/RL.
Drones hit two fuel and lubricant storage depots in the settlements of Yartsevo and Rozdorove in the Smolensk region, causing major fires and prompting the evacuation of employees, the source said.
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"26,000 cubic meters of Russian fuel were stored in these depots. After powerful explosions, a large-scale fire started at the facilities and forced the evacuation of personnel," RFE/RL's source said.
The SBU considers the logistics facilities that supply the Russian Army with fuel to be legitimate military targets, the source added.
Earlier on April 24, Smolensk Governor Vasily Anokhin reported that Ukrainian drones struck fuel and energy facilities in his region, setting them on fire.
"Our region is again under attack by Ukrainian UAVs," Anokhin wrote, adding that there were no casualties and that the fires were being put out by emergency workers in the Smolensk and Yartsevo districts.
Separately, eyewitnesses reported fires at the Smolensk and Yartsevo oil refineries. The Astra Telegram channel published a video filmed by eyewitnesses purporting to show a large fire at one refinery.
Confronted with an increasing lack of air defense systems, weapons, and ammunition as Western aid dries up, Kyiv has increasingly resorted to air and naval drone strikes deep inside Russian territory, targeting both military installations and critical oil-refining capabilities.
The strikes are part of an effort to cut fuel supplies to the Russian military and also cut export revenues that Moscow uses to fund the war.
Earlier this month, the Istories website said Ukrainian drones might have destroyed 15 percent of Russia's oil refinery facilities, while the Russian statistics service said that by the end of last month, the country's gasoline production had decreased by 14.3 percent and diesel production had reduced by seven percent.
According to British intelligence, as of March 23, Russia lost at least 10 percent of its oil refinery capacity due to drone strikes.
London believes the strikes are causing financial losses for Russia by affecting its domestic fuel market.