Ukrainian drones hit a Russian oil refinery in the city of Ryazan overnight, causing a fire and damaging equipment at one of Russia's biggest refineries, four industry sources told Reuters on Friday.

Ukraine on Sunday said that it repeatedly struck an oil refinery in Russia’s Ryazan region, the second such attack claimed by Kyiv this week. A statement by Ukraine’s General Staff claimed that the country’s armed forces, together with Ukraine’s Defense Intelligence, repeatedly struck facilities of the Ryazan Oil Refining Company.