This is according to industry sources and Reuters calculations.In August and September, several major refineries were hit by drone attacks, including:Kirishinefteorgsintez (owned by Surgutneftegaz),the Volgograd refinery (owned by Lukoil),and a group of Samara refineries operated by Rosneft.According to market participants, unplanned shutdowns at several key plants reduced fuel exports while increasing shipments of crude oil.In September, total exports of petroleum products through Baltic ports — Primorsk, Vysotsk, St. Petersburg, and Ust-Luga — fell by 15.4% to 4.36 million tonnes, according to market data.Exports through Black Sea and Azov ports dropped by 23.2% compared with August — to 2.52 million tonnes.Shipments from Arctic ports Murmansk and Arkhangelsk slightly increased by 1.8% to 30.2 thousand tonnes.Meanwhile, fuel loading at Russia’s Far Eastern ports decreased by 1.5% month-on-month — to 661.3 thousand tonnes, according to sources and Reuters estimates.On October 6, it was reported that one of Russia’s largest oil refineries, located in the city of Kirishi in the Leningrad region, halted operations at its main crude processing unit after a Ukrainian drone strike on October 4.