Vasily Anokhin, the governor of Smolensk region -- which borders Ukraine -- said that Russian air defence systems had "suppressed an attack by Ukrainian" drones in Yartsevo district.

"The wreckage of one of the unmanned aerial vehicles fell on the territory of an oil depot. As a result, a fuel spill occurred and a fire started in the fuel and lubricants," Anokhin wrote on social media early Tuesday.

He added that rescue services were still at work, and that there was "no threat" to residential buildings around the area.

Russia's defence ministry reported Tuesday that 68 Ukrainian UAVs were downed overnight, with 10 destroyed over Smolensk region.

Kyiv has struck several Russian energy facilities throughout the nearly three-year conflict, claiming the hits were fair retaliation for Moscow's large-scale attacks on its own electricity grid.

Russia's border regions are frequently targeted by Ukrainian aerial attacks, and both sides have escalated their bombardments over the last few months.

Tuesday's drone attack came a day after Russia and Ukraine swapped more than 300 prisoners of war in an operation brokered by the United Arab Emirates ahead of New Year's Eve.

The two sides have exchanged hundreds of captive soldiers since Russia began its military assault on Ukraine in February 2022 -- one of the few areas of cooperation.