A Ukrainian drone triggered a fire at Russia's Kursk Nuclear Power Plant after being downed overnight, damaging a transformer and forcing a 50% reduction in output at one of its reactors, the plant's press service said early Sunday.
The facility said on Telegram that Russian air defenses shot down the drone at 12.26 am local time (2126GMT), with the impact detonating on site. No casualties were reported.
The blast set off a blaze that was quickly extinguished but damaged an auxiliary transformer, leaving Unit 3 operating at half capacity, the statement said.
"Currently, Unit 3 is in operation at the Kursk Nuclear Power Plant. Unit 4 is undergoing scheduled maintenance. Units 1 and 2 are operating without generating power," the statement said, adding that radiation levels at the plant and surrounding areas remain within normal limits.
The International Atomic Energy Agency (IAEA) said on US social media company X that it was aware of reports that a transformer had caught fire due to "military activity." Director General Rafael Grossi said: "Every nuclear facility must be protected at all times," though the agency noted it had no independent confirmation of the incident.
The Russian Defense Ministry later claimed its forces shot down 95 Ukrainian drones overnight across 13 regions, including Kursk, as well as in Crimea, which Moscow annexed in 2014.
Kursk Governor Alexander Khinshtein warned on Telegram that strikes on such facilities "are a threat to nuclear safety, crossing all boundaries of international conventions."
Ukrainian authorities have not yet commented on the reports.
The Kursk Nuclear Power Plant, one of Russia's largest, supplies power to 19 regions in the Central Federal District. It lies about 40 kilometers (24.8 miles) west of the city of Kursk and 93 kilometers (57.7 miles) from the Ukrainian border. Ukraine launched an incursion into the border region on Aug. 6 last year.
Separately, Aleksandr Drozdenko, governor of Russia's northwestern Leningrad region surrounding the city of St. Petersburg, reported a fire at the terminal in the settlement of Ust-Luga following the crash of a downed drone.
Drozdenko claimed on Telegram that 10 Ukrainian drones were shot down over the Ust-Luga port, situated near Russia's border with Estonia, early Sunday. Later, he said, the blaze at the terminal had been extinguished and that no casualties were reported.
He added that Novatek, the Russia-based natural gas producer operating the terminal, started repair and restoration work at the site.
Ukraine's General Staff later confirmed that the military, together with the country's Security Service, inflicted damage to infrastructure at the Ust-Luga terminal, which it defined as a key logistics hub for Russia in the Baltic Sea used for energy exports through its "shadow fleet"-sea vessels allegedly used to skirt oil sanctions on Moscow.
It also claimed to have damaged multiple "logistical facilities" in the Belgorod and Voronezh regions, which it claimed "ensure the functioning and combat supply of military units" of the Russian army.
