An overnight Ukrainian drone attack hit Russia’s Andreapol oil pumping station, part of the oil export route via the Baltic Sea port of Ust-Luga, causing a fire and oil products to leak, a source in the Security Service of Ukraine said on Wednesday.

The attack also hit a Russian missile storage facility in Russia’s Tver region, causing a string of explosions, the source told Reuters.

The source said the filtration pump site and tanks with additives were damaged in the attack and that supplies via the main pipeline to the Ust-Luga terminal had temporarily been suspended.

A source in Russia’s oil pipeline monopoly Transneft said there had been no disruptions and described the damage in Tver region as limited.

Ukrainian forces have stepped up drone strikes on Russian military and energy facilities in recent weeks to raise the cost of the war for Moscow as the third anniversary of its full-scale invasion of Ukraine approaches next month.

Its military said earlier on Wednesday that it had struck an oil refinery in Russia’s Nizhny Novgorod region in an overnight drone attack and caused a large fire.

Russia has conducted regular drone strikes on targets in Ukraine since 2022.

The source said the attack on the oil pumping station and missile storage facility was a joint operation conducted by the SBU security agency and Ukraine’s Special Operations Forces.