A source in Ukraine's security services told the Kyiv Independent that drones operated by the Security Service of Ukraine (SBU) targeted an oil depot in Belgorod Oblast and an electrical substation in Lipetsk Oblast in Russia overnight on May 13.
SBU drones were behind the attack on the Eletskaya substation in Lipetsk Oblast, where a fire was reported by local Russian authorities, the source said.
The substation reportedly powers the Russian railroad, the Stanovaya oil pumping station, and ensures transit between the Lipetsk, Orel, and Bryansk power systems.
The Oskolneftsnabzhenie oil depot near the city of Stary Oskol in Belgorod Oblast also came under attack, the source said, without specifying the consequences.
"Russian oil industry that supplies Russia's war effort against Ukraine will remain a legitimate target for the SBU," the source said.
Ukraine's military intelligence agency (HUR) claimed on May 13 it was behind the attack on the oil refinery in Volgograd. The Kaluganefteprodukt oil depot and the Novolipetsk metallurgical plant were also reportedly struck by drones.
Two days before, the Security Service of Ukraine (SBU) attacked an oil refinery, Gazprom Neftekhim Salavat, in the Republic of Bashkortostan, and two oil depots in Krasnodar Krai, according to the Kyiv Independent's source.
Strikes against Russian energy targets have prompted criticism from U.S. officials, who have made it clear that Washington does not support Ukraine's attacks on oil refineries, citing fears that it could threaten the global energy market.
In response, President Volodymyr Zelensky said that Kyiv has the right to use its own weapons to strike deep inside Russia.