Ukrainian drones hit a Russian oil refinery in the city of Ryazan overnight, causing a fire and damaging equipment at one of Russia's biggest refineries, four industry sources told Reuters on Friday.

The reported strike comes two nights after Ukrainian forces launched a joint attack against the refinery that allegedly damaged multiple on-site facilities.

Ukrainian drones struck a Russian oil refinery in Ryazan, causing a fire and damaging critical equipment. The attack set oil storage ablaze and damaged a railway rack and hydrotreater unit. Russia's Defence Ministry reported repelling 121 drone attacks and Ukraine confirmed its strike on the facility.