Ukrainian drones struck a major oil refining and petrochemical complex deep inside Russia on Thursday, continuing a campaign aimed at disrupting Moscow's vital oil sector. The overnight attack hit the Gazprom Neftekhim Salavat complex in Russia's republic of Bashkortostan, located approximately 1,300 kilometers (800 miles) from Ukraine's border, according to Ukraine's General Staff.

This incident marks the fourth attack in three days on Russian energy facilities. The complex processes up to 74 million barrels of oil annually, producing gasoline, diesel fuel, and other products. Russia's Bashkortostan governor, Radiy Khabirov, confirmed a drone attack wounded two civilians and started a fire in an industrial zone in Salavat. Wildberries, Russia's largest online retailer, also reported a fire at one of its facilities in the same zone, which was evacuated.

Earlier this week, a Russian refinery in Orsk, located in the Orenburg region near the border with Kazakhstan, was hit by Ukrainian drones and has suspended operations. The regional governor, Yevgeny Solntsev, stated that "key infrastructure, which cannot be restored at this time" was struck, including foreign equipment. He noted that due to international sanctions, repairs could take up to six months, an admission of the difficulties caused by Ukrainian attacks.

Kyiv officials have stated that these drone assaults aim to compel Russian President Vladimir Putin to seek a peace deal, though there is no indication that this strategy is currently effective. Russia remains one of the world's largest energy producers, with oil revenues forming a significant part of its economy.

The attacks on Russian infrastructure come as Russia continues its own strikes on Ukraine. In the period from Wednesday to Thursday, Russian attacks involving 133 long-range drones killed at least four people and wounded eight others across Ukraine. A drone strike on a passenger train in the Odesa region killed the engineer and his assistant, according to Ukraine's state railway company. Two men were also killed in the southern city of Kherson by a Russian drone on Wednesday evening.

Ukraine has expressed a critical need for more U.S.-made Patriot interceptor missiles to counter Russia's ballistic missile and drone attacks. Ukrainian President Volodymyr Zelenskyy has stated that Ukraine has significantly fewer Patriot interceptors this year compared to the previous year and has appealed to the United States to supply a portion of its stock to help Ukraine defend its infrastructure, particularly its power grid, during the winter months.

In the first half of the current year, European countries paid U.S. defense companies at least 3 billion euros ($3.5 billion) for military equipment supplied to Ukraine, according to a report by Germany's Kiel Institute. While military aid to Ukraine has remained close to last year's levels, financial and humanitarian aid has seen a substantial decrease.