A fire has been put out at a nuclear power plant in Russia's western Kursk region and air defences have shot down a Ukrainian drone, Russian officials have said, BBC reported.

The drone detonated when it fell and damaged a transformer, but radiation levels were normal and there were no casualties, a post from the plant's account on messaging app Telegram said.

The United Nations' International Atomic Energy Agency (IAEA) has repeatedly called on both Russia and Ukraine to show maximum restraint around nuclear facilities in the war.

Ukraine is celebrating its independence day on Sunday, which marks the country's declaration of independence from the Soviet Union in 1991, according to BBC.