KYIV, Ukraine (AFP) — An overnight drone attack set several oil storage tanks ablaze near the town of Azov in southern Russia on Tuesday, sparking a large fire, local officials said.

Ukraine did not immediately claim responsibility but it has carried out similar attacks on Russian energy facilities before, arguing they are fair targets given that they fuel Moscow’s military.

“Oil product tanks caught fire in Azov as a result of a drone attack. According to preliminary data, there were no casualties,” the governor of the local Rostov region, Vasily Golubev, said on Telegram.

Video published by the emergencies ministry showed thick smoke and flames billowing out of what appeared to be multiple oil storage tanks in an undisclosed location.

Officials did not say how many drones were involved in the attack.

Some 200 firefighters and emergency personnel were deployed to deal with the blaze, which spanned an area of at least 3,200 square meters, the emergencies ministry said.

The Rostov region sits directly across the border from Ukrainian and is home to the operational headquarters overseeing Russia’s invasion.

On the battlefield, Ukraine said that Russian forces were fighting to enter the outskirts of Chasiv Yar, a flashpoint town of the war in the east whose capture could accelerate Russian advances.

Ukraine’s eastern region of Donetsk, where war-scarred Chasiv Yar lies, has borne the brunt of fighting over more than two years and the Kremlin claims the region is part of Russia.

“The enemy keeps trying to advance to the microdistrict Novy in the town of Chasiv Yar,” Ukraine’s military said in a briefing, adding that fighting was “currently taking place.”

Further south, it said Moscow’s forces were also pushing towards Pokrovsk, where they were closing in on a key road that would complicate supplies between strategic hubs in the region.

Ukraine’s air force, meanwhile, said it had downed 10 Iranian-designed attack drones launched by Russian forces overnight.