A refinery in southwestern Russia owned and operated by state oil giant Rosneft has halted roughly half of its crude processing capacity following a drone attack from Ukraine over the weekend, industry sources told Reuters on Monday. On Saturday, Dmitry Azarov, governor of the Samara region where Rosneft’s Kuibyshev oil refinery is located, said that the facility was attacked by drones. One of the two primary crude refining units at the refinery caught fire, the governor said, as quoted by Russian news agency Interfax. There were no casualties, Azarov added. Ukraine has stepped up attacks on oil refineries in Russia in recent weeks, which have reduced Russian refining capacity, and which, reportedly, have the White House concerned about rising international prices.