Editor's note: This is a developing story and is being updated.Ukrainian forces attacked a Russian oil depot in Engels, Saratov Oblast, overnight on Jan. 8, the General Staff of Ukraine's Armed Forces said.The operation, carried out jointly by Ukraine's military intelligence, the Unmanned Systems Forces, and other units, targeted the Kristal Plant used to supply fuel to the nearby Engels-2 airbase, the military said.The statement comes shortly after Russian authorities reported a drone attack in the area, with footage of the burning oil facility circulating on social media.The city of Engels lies around 600 kilometers (370 miles) from the front lines in Ukraine.