MOSCOW, July 15 (Reuters) - Russian oil refineries reduced their throughput in the first half of the year by 4% year on year to 131.8 million metric tons, Reuters calculations based on data from industry sources showed on Monday, as Ukraine hit the facilities with drones.

That is in line with an increase in the offline refining capacity.

Russia's oil refinery output declined mainly due to maintenance at the Rosneft-owned Tuapse oil refinery, which produced by 3.6 million fewer tons in the first half of the year, as well as 2.7 million tons less at the Lukoil-controlled NORSI plant and 1.1 million tons less at Rosneft's Syzran refinery.

Russia and Ukraine have both used drones to strike critical infrastructure, military installations and troop concentrations in their more than two-year conflict, with Kyiv hitting Russian refineries and energy facilities in recent months.

According to the data from sources, Russia reduced gasoline production in the first half of the year by 3.2% on a daily basis from the same period in 2023 to 21.2 million tons, due to gasoline exports ban.

Output of diesel for the period declined by 4.3% to 42.4 million tons, while fuel oil production fell by 7.4% to 18.5 million tons.

However, production of jet fuel increased by 3.2% to 5.4 million tons, the data from sources showed. (Reporting by Reuters, Editing by Louise Heavens)