Ukrainian drones strike major oil refinery deep inside Russia, setting it ablaze

KYIV, Ukraine (AP) — Ukrainian drones struck a major refinery deep inside Russia, military officials said Thursday, the fourth in three days in Kyiv's ongoing campaign to choke Moscow's vital oil sector.

Russia is one of the world's biggest energy producers, with oil providing an economic mainstay as its military tries to push deeper into Ukraine in a slow and costly advance more than four years after Moscow launched its full-scale invasion.

READ MORE: Ukrainian drone attack on oil hub deep inside Russia kills 13, official says

The attacks have dented Russia's refining capacity, causing shortages at gas stations. Kyiv officials say the onslaught is meant to compel Russian President Vladimir Putin to seek a peace deal, but there's no sign that strategy is working.

Ukraine's General Staff said its forces struck the Gazprom Neftekhim Salavat oil refining and petrochemical complex in Russia's republic of Bashkortostan overnight, causing a fire at the facility.

Bashkortostan Gov. Radiy Khabirov said only that a drone attack wounded two civilians and started a fire in an industrial zone of Salavat.

Wildberries, Russia's biggest online retailer whose giant warehouses have repeatedly been struck by Ukrainian drones, said a fire started at one of its facilities in the Salavat industrial zone after the overnight attack. The company said the facility was evacuated but that goods were not being stored there.

The attack came a day after Ukrainian missiles and drones blitzed a major Russian naval base on the Black Sea.

Elsewhere, four explosives experts from Russia's Emergency Ministry and a security guard were killed Thursday after an unspecified Ukrainian weapon blew up in Sevastopol, said Mikhail Razvozhayev, the Russian-installed governor for the port city in illegally annexed Crimea.

They were inspecting the site of a Ukrainian attack when "an enemy weapon detonated," he said.

Also in Sevastopol, a Russian serviceman was killed by an explosion, and a Russian woman, allegedly acting on the orders of Ukrainian intelligence agencies, was detained as a suspect, the Crimean branch of Russia's Federal Security Service said Thursday.

Meanwhile, a Russian refinery in Orsk that was hit by Ukrainian drones earlier this week has suspended operations, Orenburg region Gov. Yevgeny Solntsev said.

He said that "key infrastructure, which cannot be restored at this time" was attacked, including foreign equipment, and repairs could take up to six months because of international sanctions, Solntsev said in a rare public admission in Russia of the problems Ukrainian attacks are causing.

Ukraine's General Staff had reported striking the Orsk refinery near the border with Kazakhstan on Tuesday.