Russian officials and a Ukrainian military official said on Saturday that Ukrainian drones carried out airstrikes overnight on several Russian oil facilities, including two oil refineries in the Samara region, an oil depot in the Crimean Peninsula, and a port on the Baltic Sea used for exporting petroleum products.

Ukrainian forces have intensified their attacks on Russian oil depots and refineries over the past few weeks.

On March 29, the strategic port of Ust-Luga suffered material damage that led to a fire as a result of a Ukrainian drone attack. The port is one of Russia’s largest oil export terminals and is operated by the state-owned company Transneft, which holds a monopoly over oil pipelines.

These strikes come amid a recurring escalation by Ukraine targeting Russian oil export facilities and refineries, in an attempt, to undermine economic support for Russia’s military operations.