A drone strike has sparked a fire at a refinery in Russia, with some reports indicating the target was a Gazprom facility. The location of the refinery is unclear, with different sources suggesting it could be in Bashkortostan or Krasnodar Krai, and the specific target also uncertain, with some reports mentioning an oil refinery or a petrochemical plant. The incident appears to be part of a series of Ukrainian strikes on Russian oil refineries.