Russia accused Ukraine on Sunday of launching drone attacks that sparked a fire at a nuclear power plant in its western Kursk region overnight, as Ukraine celebrated 34 years since its independence.

Russian officials said several power and energy facilities were targeted in the overnight strikes. The fire at the nuclear facility was quickly extinguished with no injuries reported, according to the plant's press service on Telegram. While the attack damaged a transformer, radiation levels remained within normal ranges.

The United Nations' nuclear watchdog said it was aware of media reports that a transformer at the plants had caught fire 'due to military activity,' but hadn't received independent confirmation. It said its director-general, Rafael Mariano Grossi, said that 'every nuclear facility must be protected at all times.'