Ukrainian drones attacked a Rosneft-owned (ROSN.MM) oil refinery in southern Russia in the latest such strike on Russian energy infrastructure, a Ukrainian source said on Thursday.
Local officials in Russia said there was a fire overnight at the export-oriented unit in the town of Tuapse, but it was extinguished.
"The vacuum unit was on fire. According to preliminary information, there were neither casualties nor injured," Sergei Boiko, the head of Tuapse district, said on Telegram.
Rosneft, Russia's largest oil producer, has not commented.
The Ukrainian source said the SBU security service hit the refinery with drones and would continue attacking facilities providing fuel for Russia's nearly two-year invasion.
"The SBU strikes deep into the Russian Federation and continues attacks on facilities which are not only important for the Russian economy, but also provide fuel for the enemy troops," the source told Reuters.
Unofficial Telegram channels showed pictures of the blaze and also said drones had been responsible.
The strike would be at least the fourth on a major Russian energy infrastructure target over the past week, including an attack on a Baltic Sea fuel export terminal and processing complex at the port of Ust-Luga, which ships oil products.
Ukraine - which tranships natural gas for Kremlin-controlled Gazprom (GAZP.MM) to Europe - appears to be stepping up attacks on major Russian oil production and export facilities.
The attack will heighten concerns over global energy supplies. Oil prices rose on Thursday after a fresh attack by Houthi forces on ships off Yemen's coast.
The Tuapse plant's annual capacity is 12 million metric tons (240,000 barrels per day). It produces naphtha, fuel oil, vacuum gasoil and high-sulphur diesel, and supplies fuel mainly to Turkey, China, Malaysia and Singapore.
In 2023, the plant processed 9.378 million tons of crude oil, producing 3.306 million tons of gasoil and 3.123 million tons of fuel oil.