KRAMATORSK, Ukraine >> Moscow-backed separatists pounded eastern Ukraine’s industrial Donbas region Friday, claiming to capture a railway hub, as Ukrainian officials pleaded for the sophisticated Western weapons they say they need to stop the onslaught.

The advance of Russian forces raised fears that cities in the region would undergo the same horrors inflicted on the people of the port city Mariupol in the weeks before it fell.

The fighting Friday focused on two key cities: Sievierodonetsk and nearby Lysychansk. They are the last areas under Ukrainian control in Luhansk, one of two provinces that make up the Donbas and where Russia-backed separatists have already controlled some territory for eight years. Authorities say 1,500 people in Sievierodonetsk have already died since the war’s start three months ago. Russia-backed rebels also said they’d taken the railway hub of Lyman.

The governor of Luhansk warned that Ukrainian soldiers may have to retreat from Sievierodonetsk to avoid being surrounded. But he predicted an ultimate Ukrainian victory. “The Russians will not be able to capture Luhansk region in the coming days, as analysts predict,” Serhiy Haidai wrote on Telegram on Friday. “We will have enough forces and means to defend ourselves.”

Ukrainian President Volodymyr Zelesnskyy also struck a defiant tone. In his nightly video address Friday, he said: “If the occupiers think that Lyman or Sievierodonetsk will be theirs, they are wrong. Donbas will be Ukrainian.”

For now, Sievierodonetsk Mayor Oleksandr Striuk told The Associated Press that “the city is being systematically destroyed — 90% of the buildings in the city are damaged.”

Striuk described conditions in Sievierodonetsk reminiscent of the battle for Mariupol, located in the Donbas’ other province, Donetsk. Now in ruins, the port city was constantly barraged by Russian forces in a nearly three-month siege that ended last week when Russia claimed its capture. More than 20,000 of its civilians are feared dead.

Before the war, Sievierodonetsk was home to around 100,000 people. About 12,000 to 13,000 remain in the city, Striuk said, huddled in shelters and largely cut off from the rest of Ukraine. At least 1,500 people have died there because of the war, now in its 93rd day. The figure includes people killed by shelling or in fires caused by Russian missile strikes, as well as those who died from shrapnel wounds, untreated diseases, a lack of medicine or being trapped under rubble, the mayor said.

In the city’s northeastern quarter, Russian reconnaissance and sabotage groups tried to capture the Mir Hotel and the area around it, Striuk said.

Hints of Russia’s strategy for the Donbas can be found in Mariupol, where Moscow is consolidating its control through measures including state-controlled broadcast programming and overhauled school curricula, according to an analysis from the Institute for the Study of War, a Washington think tank.

Gen. Phillip Breedlove, former head of U.S. European Command for NATO, said Friday during a panel mounted by the Washington-based Middle East Institute that Russia appears to have “once again adjusted its objectives, and fearfully now it seems that they are trying to consolidate and enforce the land that they have rather than focus on expanding it.”

That aggressive push could backfire, however, by seriously depleting Russia’s arsenal. Echoing an assessment from the British Defense Ministry, military analyst Oleh Zhdanov said Russia was deploying 50-year-old T-62 tanks, “which means that the second army of the world has run out of modernized equipment.”

Russia-backed rebels said Friday that they had taken over Lyman, Donetsk’s large railway hub north of two more key cities still under Ukrainian control. Ukrainian presidential adviser Oleksiy Arestovych acknowledged the loss Thursday night, though a Ukrainian Defense Ministry spokesperson reported Friday that its soldiers countered Russian attempts to completely push them out.

As Ukraine’s hopes of stopping the Russian advance faded, Foreign Minister Dmytro Kuleba pleaded with Western nations for heavy weapons, saying it was the one area in which Russia had a clear advantage.

“Without artillery, without multiple launch rocket systems we won’t be able to push them back,” he said.

The U.S. Defense Department would not confirm a CNN report that the Biden administration was preparing to send long-range rocket systems to Ukraine, perhaps as early as next week. “Certainly we’re mindful and aware of Ukrainian asks, privately and publicly, for what is known as a multiple launch rocket system. And I won’t get ahead of decisions that haven’t been made yet,” Pentagon spokesman John Kirby said.

Russian Foreign Minister Sergei Lavrov warned that providing rockets that could reach his country would represent “a most serious step toward unacceptable escalation.” He spoke in an interview with RT Arabic that aired Friday.

Just south of Sievierodonetsk, volunteers hoped to evacuate 100 people from a smaller town. It was a painstaking process: Many of the evacuees from Bakhmut were elderly or infirm and needed to be carried out of apartment buildings in soft stretchers and wheelchairs.

Minibuses and vans zipped through the city, picking up dozens for the first leg of a long journey west.

“Bakhmut is a high-risk area right now,” said Mark Poppert, an American volunteer working with British charity RefugEase. “We’re trying to get as many people out as we can.”

To the north, neighboring Belarus — used by Russia as a staging ground before the invasion — announced Friday that it was sending troops toward the Ukrainian border.

In Russia’s Far East, a legislative deputy offered a rare display of opposition to the war in Ukraine, demanding the end of the military operation and the withdrawal of Russian troops. “We understand that if our country doesn’t stop the military operation, we’ll have more orphans in our country,” Leonid Vasyukevich of the Communist Party said Friday at a meeting of the Primorsk regional Legislative Assembly in the Pacific port of Vladivostok.

His comments, which he addressed to President Vladimir Putin, were shown in a video posted on a Telegram. Another deputy followed to support Vasyukevich’s views. But the legislative assembly’s chairman issued a statement afterward calling the remarks a “political provocation” not supported by the majority of lawmakers.

Karmanau reported from Lviv, Ukraine. Andrea Rosa in Kharkiv, Ukraine, and AP journalists around the world contributed.