Ukrainian forces staged an overnight drone attack that set several oil storage tanks ablaze near the town of Azov in southern Russia, sparking a large fire, a source in Kyiv told AFP on Tuesday.

Kyiv has carried out similar attacks on Russian energy facilities before, arguing they are fair targets given that they fuel Moscow's military.

Russia has also launched dozens of devastating attacks on Ukrainian power plants throughout its two-year invasion, crippling the country's energy grid.

"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.

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

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

"The (Security Service of Ukraine) SBU will continue to impose 'drone sanctions' on Russia's oil refining complex and reduce the enemy's economic potential, which provides the aggressor with resources to wage war against Ukraine," the defence-linked source said.

It also claimed that SBU drones have carried out more than 20 successful attacks on Russian oil facilities in various regions.

Some 200 firefighters and emergency personnel were deployed to deal with the blaze, which spanned an area of at least 3,200 square metres (3,800 square yards), Russia's emergencies ministry said.

The Rostov region sits directly across the border from Ukraine 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.