Russian air defences shot down 57 Ukrainian drones over its southern Krasnodar region overnight Saturday, the Russian Defence Ministry said Sunday morning.

Local military officials said drone debris hit an oil refinery in the town of Slavyansk-on-Kuban, but there was no fire or damage. Local news outlet Astra published videos appearing to show an explosion at the refinery as it was hit by a drone. The videos could not be independently verified.

Nine long-range ballistic missiles and a drone were destroyed over the Russia-occupied Crimean Peninsula, following Friday morning's massive Ukrainian drone attack that cut off power in the city of Sevastopol.

A further three drones were shot down over the Belgorod region, which borders Ukraine. According to regional Governor Vyacheslav Gladkov, a church roof was set on fire by falling drone debris, but there were no casualties.

In Ukraine, air force officials said air defence shot down all 37 Russian drones launched against the country overnight.

In the northeastern Kharkiv region, where Moscow recently launched a new offensive, regional Governor Oleh Syniehubov said Sunday morning that one person died and 11 were wounded as a result of shelling over the previous day.

Ukrainian troops are fighting to halt Russian advances in the Kharkiv region that began late last week.

Russian President Vladimir Putin said on Friday during a visit to China that Moscow's offensive in the Kharkiv region aims to create a buffer zone but that there are no plans to capture the city.