Ukraine's Security Service (SBU) was behind a sweeping wave of drone attacks on several Russian regions on March 13 that reportedly set a Rosneft refinery on fire and targeted other economic and military objectives, a Ukrainian intelligence source told RFE/RL.
Russia's Defense Ministry earlier said its air defenses shot down 65 Ukrainian drones over six regions -- 35 in Voronezh, 25 in Belgorod, eight in Bryansk and Kursk each, one in Leningrad, and one on Ryazan region.
Regional officials reported that the Rosneft oil refinery in Ryazan was struck, a day after another drone attack seriously damaged a LUKoil refinery.
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Pavel Malkov, the governor of Ryazan, some 180 kilometers southeast of Moscow, said the local Rosneft oil refinery, Russia's seventh-largest, was on fire as a result of a drone attack.
There were also casualties, according to preliminary information, Malkov wrote on Telegram, without providing further details.
The Shot Telegram channel reported that the attack on the Rosneft subsidiary Ryazannefteprodukt also injured two people.
Russian news agency RIA Novosti later quoted emergency services as saying that four drones had hit the refinery. The fire, which affected two tanks used in the processing of oil products on an area of some 175 square meters, was later extinguished, it said.
The source, who is in security enforcement and spoke on condition of anonymity to RFE/RL, said that three Russian oil refineries -- one in Ryazan, one in Kstovo in the Nizhny Novgorod region, and one in Kirishi in the Leningrad region -- were targeted by Ukrainian drones as Kyiv seeks to inflict as much damage as possible to Russia's economy
"We have been systematically implementing a detailed strategy to diminish the economic potential of the Russian Federation. Our task is to deprive the enemy of resources and reduce the flow of oil money and fuel, which the Russia directs toward the war and the murdering of our citizens," the source said
Ukrainian drones also targeted a Russian air base in Buturlinovka and a military airfield in Voronezh region, the source said.
Separately, an SBU source who wished to remain anonymous confirmed to Ukrayinska Pravda that the strikes had been orchestrated by the agency.
"We are at war with everything that finances the Russian military and the war. And Russia is at war with civilians and high-rise buildings," Andriy Yermak, the head of Ukraine’s presidential office, wrote on Telegram, without directly confirming the attacks.
In Belgorod, regional Governor Vyacheslav Gladkov said an apartment building was struck but there were no injuries, while according to TASS, the facade of the regional headquarters of the Federal Security Service (FSB) was damaged and windows were broken.
The March 13 attacks came a day after another sweeping wave of strikes on multiple targets in Russia that reportedly started fires at two major oil facilities.
The attacks damaged LUKoil's NORSI refinery, Russia's fourth-largest, in the Nizhny Novgorod region about 775 kilometers from the Ukrainian border and hit an oil depot in Oryol, 116 kilometers from Ukraine.
Also on March 12, the Freedom of Russia Legion, the Russian Volunteer Corps, and the Siberian Battalion, which consist of Russian citizens who have been fighting alongside Ukrainian forces in the war, claimed to have launched cross-border attacks into Russia territory.
The Kremlin said Russian forces repelled the incursions and inflicted heavy losses on the armed groups. Neither claim could be independently verified.
Meanwhile, Russian air strikes killed at least two people and wounded several others on March 13 in Ukraine's Donetsk and Sumy regions, officials said.
Two civilians were killed and 11 wounded in the eastern Donetsk region in the bombardment of a high-rise residential building in the city of Myrnohrad, regional Governor Vadym Filashkin said on Telegram.
In the northeastern region of Sumy, a Russian drone attack on a five-story apartment building destroyed 30 apartments and caused a number of casualties, the region's military administration said on Telegram.
Ten people were rescued from the rubble, eight of whom sustained injuries, it said.