Ukraine Strikes Oil Depot Near Russian Air Base, Ukrainian Military Says

Ukraine attacked an oil depot near a critical military airfield in southern Russia on Wednesday, the Ukrainian military said, the latest strike in a campaign to inflict pain deep inside the country even as Kyiv’s forces are losing ground at home on the battlefield.

The military said it had struck the Kristall oil storage facility in Engels, around 300 miles from the border between the two countries. It said the depot supplied fuel to the Engels airfield, which it has said is a staging ground for Russia’s long-running attacks on Ukrainian energy infrastructure, and which hosts some of Russia’s long-range nuclear-capable bombers.

A Russian official wrote on the Telegram messaging app that a “massive” drone attack had targeted Engels. Roman Busargin, the governor of the Saratov region, said that air defenses had intercepted the drones but that falling debris had hit an “industrial facility” and ignited a fire. No one was hurt, Mr. Busargin wrote.

Kyiv has repeatedly targeted the base, trying to limit the strikes on Ukraine’s energy system, which have plunged cities into darkness, battering the Ukrainian grid and forcing officials to scramble for alternative power options.

The latest attack came as Ukrainian forces are pressing what appears to be a renewed offensive in the Kursk region in western Russia. Both sides have reported fierce fighting over the past few days in Kursk, where Ukrainian troops seized about 500 square miles of territory in a surprise cross-border incursion last summer.

Russia has since regained roughly half of the territory it lost. Analysts have said the renewed offensive appears to be Ukraine’s attempt to regain momentum and project strength before President-elect Donald J. Trump’s inauguration.