Ukraine's Defense Intelligence (HUR) drones have attacked a rare refinery in Russia's Orenburg.

Axar.az informs, citing RBC-Ukraine, this enterprise is the only one in Russia that produces helium for missiles.

Local residents could see the drones flying overhead and also reported a series of explosions in the area of the refinery.

The Orenburg helium refinery is the only helium production enterprise in Russia and one of the largest in Europe. The plant's annual capacity allows for processing about 15 billion cubic meters of natural gas.

Helium is widely used in missile manufacturing, the space industry, and aviation. It is a critical component required to create pressure in fuel tanks, ensuring the uninterrupted supply of fuel to missile engines.