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.

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.

The targeted refinery is one of Russia’s biggest

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.

The complex, located southeast of Moscow about 1,300 kilometers (800 miles) from Ukraine’s border, is one of Russia’s largest such facilities, the General Staff said in a Telegram post. The plant processes up to 74 million barrels of oil annually, producing gasoline, diesel fuel and other products, it said.

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.

It was not possible to independently verify either side’s reports.

Russian official says refinery repairs could take 6 months

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.

Russian drone hits a Ukrainian passenger train, killing 2

Russia has responded by hammering Ukraine with ballistic missiles, jet-powered drones and glide bombs, all of which are hard to intercept. The strikes have killed more than 16,000 civilians since the war began, according to the United Nations.

Russian attacks featuring 133 long-range drones killed at least four people and wounded eight others across Ukraine overnight, officials said.

A jet-powered Shahed drone struck a passenger train in the southern Odesa region, killing the engineer and his assistant, said Ukraine’s state railway company Ukrzaliznytsia.

A Russian drone killed two men Wednesday evening in the southern city of Kherson, regional military administration chief Oleksandr Prokudin said.

Ukraine makes little headway on obtaining Patriot missiles

Ukraine desperately wants more U.S.-made Patriot interceptor missiles that can counter Russia’s ballistic missiles, but stocks of the air defense system reportedly are low because of the Iran war.

Ukraine has two and a half times fewer Patriot interceptors than in 2025, according to President Volodymyr Zelenskyy, saying he makes calls every day to try to source some more.

He said he is asking the United States to sell 5% of the interceptor missiles they have in stock to help Ukraine make it through next winter, when Russia’s strikes focus on the power grid, according to an interview with CNN broadcast Wednesday, parts of which he posted online. So far, he said he has obtained only 1%.

In the first half of this year, European countries paid U.S. defense companies at least 3 billion euros ($3.5 billion) for military equipment they sent to Ukraine, according to a report Thursday by Germany’s Kiel Institute, which tracks assistance to Kyiv.

The Trump administration won’t provide its own aid to Ukraine but is allowing other countries to buy U.S. equipment that is sent on.

Military aid provided to Ukraine in the first half of 2026 was close to last year’s level, the Kiel Institute said, but financial and humanitarian aid was 41% lower than in 2025.

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