Nearly all major oil refineries in central Russia have either suspended operations or significantly reduced fuel production following a wave of Ukrainian drone strikes in recent days, according to official data and sources familiar with the matter.

The disruption comes as Moscow has already imposed a ban on gasoline exports from April through the end of July in an effort to stabilize domestic fuel supplies, The Caspian Post reports, citing Reuters.

Sources said the total refining capacity affected by full or partial shutdowns exceeds 83 million metric tons annually, equivalent to around 238,000 tons per day. This represents roughly one quarter of Russia’s total oil refining capacity.

The impacted refineries account for more than 30% of Russia’s gasoline production and approximately 25% of its diesel output, according to industry data. Russia’s energy ministry did not respond to requests for comment.

Ukraine has intensified its drone campaign against Russian energy infrastructure this year, with the number of targeted oil refineries reportedly doubling since January, according to social media statements by Russian officials.

In addition to refineries, the attacks have also struck pipelines and fuel storage facilities. The damage has further reduced Russian oil production, placing added pressure on Moscow’s federal budget, where oil and gas tax revenues make up around one quarter of state income.

Among the facilities targeted are the Kirishi refinery in western Russia, the Moscow oil refinery, and plants located in Nizhny Novgorod along the Volga River, as well as in Ryazan and Yaroslavl.

The Kirishi refinery, one of Russia’s largest processing plants with an annual capacity of 20 million metric tons, has reportedly been completely shut down since May 5, sources said.

Another major facility, the Nizhegorodnefteorgsintez (NORSI) refinery, which can process 17 million metric tons per year, was attacked on May 20. It remains unclear whether the refinery has been able to continue limited operations following the strike.