A drone strike has hit a key Russian oil refinery on the Ukrainian border.

The authorities of the oil refinery informed this information. News from Al Jazeera.

Officials at the Novoshakhtinsk refinery in the Rostov region say the first drone strike took place at 8:40 a.m. local time at a crude distillation unit. It caused a terrible explosion and caught fire. The second attack took place at 9:23. This time the attack is on the place where crude oil is kept.

Authorities say the next attack did not set fire to the refinery, the largest supplier of oil products in southern Russia. No one was injured.

Russia’s territory on the border with Ukraine has been attacked before. The refinery is located 6 km (5 miles) from the border.

Authorities said in a statement that as a result of terrorist activities from the western border of the Rostov region, two drones hit the technical facilities of Novoshakhtinsk. Staff have been evacuated and technical equipment has been shut down to assess the damage.

Ukraine, meanwhile, did not immediately respond to a request for comment.

Rostov Governor Vasily Golubev said the refinery had been shut down. The wreckage of two drones was found there.

The refinery started operations in 2009. Its annual refining capacity is 75 lakh tons.