Russian officials reported a large drone strike on an industrial site in Kstovo, with war-monitoring channels pointing to the Lukoil-run refinery, one of Russia's largest fuel plants.

Russian officials said a large-scale drone attack struck an industrial facility in Kstovo, a town in the Nizhny Novgorod region some 400 kilometres east of Moscow, early on Sunday. War-monitoring channels on Telegram identified the target as the Lukoil-Nizhegorodnefteorgsintez refinery, widely regarded as one of Russia's largest fuel-processing plants. Authorities have not confirmed the scale of the damage or said who carried out the strike.

The attack adds to a long-running campaign of strikes on Russian refining infrastructure since the war in Ukraine began, which has periodically forced facilities offline and strained the country's ability to process crude into diesel and other fuels for both domestic use and export. Lukoil, one of Russia's largest private oil companies, already operates under Western sanctions that restrict its access to international financing and some markets.

Russia remains one of the world's biggest diesel exporters, and any sustained disruption to its refining capacity can feed through to fuel markets well beyond its borders, at a time when European diesel supplies are already under pressure from other sourcing constraints. Analysts have said repeated strikes on refineries this size can take weeks to fully repair, depending on which units were affected.