The drone attack on an oil refinery in Tatarstan last night was a joint operation of the SBU and the GUR of the Ministry of Defense. This was reported by Ukrainska Pravda, citing its sources. 

"The nighttime "cotton" at the oil refinery in Tatarstan is a joint operation of the SBU and the GUR. A Ukrainian long-range drone hit the primary oil refining unit at the refinery in Nizhnekamsk, after which a fire broke out there," the source said.

According to the source, the capacity of this unit was 8 million tons of oil, which is 2.6% of Russia's total annual refining capacity. He also said that this refinery is one of the five largest in Russia.

"We continue to work systematically to ensure that the Russian Federation has fewer opportunities to finance its war of aggression against Ukraine. We will continue to cut off oxygen to the gas station country to minimize the flow of petrodollars to Russia's military budget," the source concluded.