Ukrainian drones struck the Kirishi oil refinery in Russia’s northwestern Leningrad region overnight, sparking a fire that regional officials said was extinguished and that Ukraine’s military reported amid a wider wave of drone attacks.

The Ukrainian General Staff reported explosions and a fire at the facility, and Leningrad regional Governor Alexander Drozdenko said three drones were downed in the Kirishi area and that falling debris ignited a blaze at the refinery. Drozdenko said no one was injured and that the fire was put out. Russian federal officials had not provided further comment as of Sunday afternoon, and independent verification of damage was not immediately available.

The Kirishi plant, operated by Surgutneftegas, produces about 17.7 million metric tons of crude per year, roughly 355,000 barrels per day, making it one of Russia’s three largest refineries by output. Ukrainian forces previously targeted the site in March, when regional officials reported only minor damage.

The Russian Defense Ministry said at least 80 Ukrainian drones were shot down overnight over Russian territory, the annexed Crimean Peninsula and the adjacent Sea of Azov. Kyiv has for months carried out strikes on energy and transport infrastructure inside Russia, which it says help degrade Moscow’s ability to sustain its war effort in Ukraine. Drones continue to be a primary weapon for both sides in the conflict.

The overnight strike came after a series of incidents that have raised concerns about the conflict spilling beyond Ukrainian territory. Multiple Russian drones crossed into Poland on Wednesday, prompting NATO to scramble fighter jets to intercept them. NATO and Polish officials said the incursions underscored long-standing anxieties among alliance members about unintended escalation.

The strikes on oil infrastructure have coincided with a seasonal increase in demand and have contributed to fuel shortages in parts of Russia. Gas stations in some regions have reported running dry, motorists have queued for fuel, and regional authorities have at times rationed or suspended sales. In response to the shortages, Russian officials announced a pause on gasoline exports, instituting a full ban through Sept. 30 and a partial ban affecting traders and intermediaries through Oct. 31.

Also in the Leningrad region overnight, Drozdenko said a diesel locomotive derailed near Gatchina, south of St. Petersburg. He said the locomotive’s driver was trapped in his cabin and later died while being transported to a hospital. Drozdenko said investigators would check for signs of sabotage.

Separately, Oryol regional Governor Andrey Klychkov reported that a bomb planted along railway lines near the town of Maloarkhangelsk killed three people, including a member of Russia’s National Guard, late Saturday and Sunday. The town is about 200 kilometers (120 miles) from the Ukrainian border. Federal authorities had not immediately commented on the cause of the explosion or any link to the wider conflict.

The incidents occurred as Russians voted in local elections in 21 regions, and the head of the Central Election Commission, Ella Pamfilova, told reporters the commission and the country’s electronic voting system were under a large wave of cyberattacks. Pamfilova characterized the activity as "an unprecedented attack" but said it would not affect vote outcomes. The election commission’s website experienced outages during voting, and Alexander Izhko of the media and digital watchdog Roskomnadzor said almost 100 denial-of-service attacks were recorded on Sunday against online resources linked to the elections.

Authorities in Moscow and regional administrations said investigations into the Kirishi incident, the derailment near Gatchina and the Oryol explosion were ongoing. The Russian government has not yet issued a comprehensive account of damage at the refinery, and international agencies had no immediate independent confirmation of the extent of any losses at the Kirishi facility.