This is stated by the governor of the republic of Bashkortostan, Radiy Khabirov, and calls the incident a "terrorist attack".
Ukraine has not confirmed the attack. The country sent drones against an oil refinery in Bashkortostan last year, in the southern end of the Ural Mountains. The refinery that was allegedly attacked on Saturday is located near the city of Ufa, 140 miles from the Ukrainian border.
The Ukrainian security service SBU stated on Friday that the country had carried out a drone attack on Primorsk, Russia's most important oil port in the Baltic Sea.
