A fire that broke out at the Kuibyshev oil refinery in Russia's Samara region overnight on March 23 had been caused by a drone attack, the regional government told Russian state-controlled news agency Interfax, citing Governor Dmitry Azarov.
In the past weeks, Ukrainian forces have launched a series of drone strikes aimed at damaging Russia's oil industry. Ukraine has hit oil refineries in multiple regions deep inside Russian territory.
Drones attacked oil refineries in the Samara region at night, followed by a primary oil refining column at the Kuibyshev facility catching fire, said Azarov. There were no casualties, he added.
The fire was extinguished in the morning, the regional authorities told Interfax.
Local residents previously reported explosions at the refinery and said the facility was on fire, according to Russian Telegram news channels.
Ukrainian forces previously struck the Kuibyshev oil refinery on March 16 in a drone strike that also targeted the region's Syzran refinery. Only the Syzran facility caught fire following the attack, Russian officials claimed.
Both refineries are owned by Rosneft, Russia's largest oil company.
Deputy Prime Minister Olha Stefanishyna said on March 22 that Russia's oil refineries are "absolutely legitimate targets" for the Ukrainian military. Her statement followed media reports that the U.S. had asked Ukraine to stop attacking the Russian oil industry.
Presidential adviser Mykhailo Podolyak denied the reports, saying Kyiv did not receive any such calls from Washington.
Ukraine's recent drone attacks knocked out about 600,000 barrels of Russia's daily oil-refining capacity, as estimated by Torbjorn Tornqvist, the director of the international energy commodities trading company Gunvor Group, Bloomberg reported on March 18.