Ukraine denied Moscow's claims on Sunday (May 31, 2026) that a Ukrainian drone struck the Russian-controlled Zaporizhzhia nuclear plant, as Kyiv launched fresh strikes overnight on Russian energy sites.

Ukraine's General Staff on Sunday (May 31, 2026) said Ukrainian drones had struck the Saratov oil refinery in southwestern Russia, causing a “large-scale fire.” It said the extent of the damage was being clarified, and claimed the refinery has been supplying Moscow's war effort.

The refinery belongs to Russia's state oil enterprise, Rosneft, and produces diesel and gasoline among other types of fuel.

The Russian local governor, Roman Busargin, said Ukrainian drones had damaged “civilian infrastructure”, but did not immediately give details. Astra, an independent Russian news channel, said an oil refinery was on fire in the city of Saratov.

Ukraine has stepped up its attacks on Russia's oil and gas facilities in recent months, arguing the energy sector both funds and directly fuels Moscow's more than 4-year-old invasion.

Drone debris also set fire to a fuel depot in Russia's southwestern Rostov region, which borders Russian-occupied eastern Ukraine, local Gov. Yuriy Slyusar reported on Telegram on Sunday (May 31, 2026). He said residents of nearby homes were evacuated.

Ukraine's General Staff on Sunday (May 31, 2026) confirmed its forces were behind the strike on the facility in the town of Matveev Kurgan. Local authorities said a drone strike on the depot had caused a large-scale fire across a wide area.

According to its General Staff, Ukraine also struck the Lazarevo pumping station in Russia's Kirov region northeast of Moscow, more than 1,200 kilometers (745 miles) from Ukrainian-controlled land. The station helps ship Russian oil from Siberia to Belarus.

Local Gov. Alexander Sokolov said drones had hit a facility in the Kirov region, without giving further details.

'Another propaganda ploy'

Kyiv denied a Russian claim that a Ukrainian drone struck the Zaporizhzhia nuclear plant, Europe's largest.

Russia's state nuclear energy company, Rosatom, said on Saturday (May 30, 2026) that the drone exploded after tearing a hole in the wall of a turbine hall. Rosatom's CEO Alexei Likhachev accused Ukraine of a “deliberate” attack.

“This afternoon, a Ukrainian kamikaze combat drone struck the turbine hall building of Power Unit No. 6, resulting in a detonation,” Mr. Likhachev said. He added there was no damage to main equipment.

Ukraine's military said it did not target or strike the plant, and described the Russian claim as “yet another propaganda ploy.” A military statement said that it adheres to international humanitarian law and is aware of the "consequences of any actions targeting nuclear facilities.”

“Along the relevant section of the front line, there was no active fighting at the time of the incident, and no weapons were used,” it added.

Rafael Grossi, head of the International Atomic Energy Agency, voiced “serious concern” in a post on X following the incident.

The IAEA said in an online statement on Sunday (May 31, 2026) that its inspectors “observed damage to the exterior of a turbine building” that was “consistent with the impact of the drone.” It gave no details of where the drone may have come from, but said radiation levels at the site remained normal.

“During a site walk down, the team saw damage to a metal access hatch located several levels up in the building, as well as a few pieces of debris and burned optical fibre remains on the ground," the agency said in a post on X. It added its inspectors had requested access to the inside of the turbine hall, “for further examination.”

Drone attacks continue

Russian forces captured the Zaporizhzhia plant in the early weeks of the war, and it remains close to the front lines in the southern Zaporizhzhia region, one of four Russia has formally annexed despite lacking full military control or international recognition for its actions.

The nuclear plant has repeatedly come under fire since Russia's full-scale invasion in February 2022, sparking fears of a nuclear accident. Moscow and Kyiv have blamed each other for targeting the plant.

Elsewhere, Ukraine's air force said on Sunday (May 31, 2026) that it had shot down 212 of 299 drones launched by Russia overnight. It said 14 drones had reached their targets, while drone debris fell in five locations.

A truck driver died early on Sunday (May 31, 2026) as drones hit a parking lot in Ukraine's northern Chernihiv region, according to local administration head Vyacheslav Chaus.

Russian drones struck the city of Dnipro and an oil refinery in Ukraine's Rivne region, causing fires, authorities said. No one was injured in either location, Ukrainian officials later reported.