On the night of February 19, drones attacked the Syzran oil refinery in the Samara region of Russia.
The governor of the region, Vyacheslav Fedorishchev, said that emergency services were working at the site.
According to Russian media, the company is owned by Rosneft and processes up to 8.9 million tons of oil per year.
The plant produces motor fuel and other petroleum products and employs more than 2,200 people.