A Telegram channel initially reported that drones attacked an oil refinery in the city of Novokuibyshevsk, publishing photos and videos showing black smoke from a fire over the city.
According to the channel, the fire broke out at the ELOU-AVT-6 (AVT-11) oil refining unit.
The channel later also reported an attack on the Syzran refinery and released footage of a fire.
Samara region Governor Vyacheslav Fedorishchev confirmed a drone attack on the region but did not mention fires at the refineries. He said one of the drones fell near a maternity hospital in Novokuibyshevsk.
The Novokuibyshevsk refinery processes more than 8.8 million tons of oil per year, while the Syzran refinery handles between 7 million and 8.9 million tons. Both facilities have previously been targeted in drone strikes.