KYIV, Ukraine (AP) — Workers digging through the rubble of an apartment building in Mariupol found 200 bodies in the basement, Ukrainian authorities said Tuesday, a grim reminder of the horrors still coming to light in the ruined city that has seen some of the worst suffering of the 3-month-old war.

The bodies were decomposing and a stench permeated the neighborhood, said Petro Andryushchenko, an adviser to the mayor. It's not clear when they were discovered.

Perched on the Sea of Azov, Mariupol was relentlessly pounded during a monthslong siege that finally ended last week after some 2,500 Ukrainian fighters abandoned a steel plant where they had made their last stand.

Russian forces already held the rest of the city, where an estimated 100,000 people remain out a prewar population of 450,000, many trapped without food, water, heat or electricity.

Ukrainian authorities have said at least 21,000 people have been killed — and accused Russia of trying to cover up the extent of the horrors by bringing in mobile cremation equipment. They have also alleged some of the dead were buried in mass graves. Strikes have also hit a maternity hospital and a theater where civilians were sheltering.

Ukrainian President Volodymyr Zelenskyy accused the Russians of waging “total war,” seeking to inflict as much death and destruction as possible on his country.

“Indeed, there has not been such a war on the European continent for 77 years,” Zelensky told Ukrainians Monday night, on the eve of the three-month anniversary of the start of the war.

The conflict began with expectations that Russia might overtake the country in a blitz lasting only days or a few weeks. But stiff Ukrainian resistance, bolstered by Western weapons, has bogged down Moscow's troops.

The Kremlin is now focused on the eastern industrial heartland of the Donbas — where Moscow-backed separatists have fought Ukrainian forces for eight years and held swaths of territory.

That grinding conflict had already claimed 14,000 lives before Russia launched its invasion of Ukraine on Feb. 24 — and even after shifting their focus there, Moscow's troops have struggled to gain ground.

Russian forces have intensified efforts to encircle and capture Sievierodonetsk and neighboring cities, the only part of the Donbas’ Luhansk region that remains under Ukrainian government control, British military authorities said Tuesday.

Russian forces have achieved “some localized successes” despite strong Ukrainian resistance along dug-in positions, the U.K. Defense Ministry said, but the fall of Sievierodonetsk and the area around it may cause logistical problems for the Russians.

“If the Donbas front line moves further west, this will extend Russian lines of communication and likely see its forces face further logistic resupply difficulties,” the ministry said.

Two top Russian officials appeared to acknowledge Tuesday that Moscow’s advance had been slower than expected — though they promised the offensive would achieve its goals.

Secretary of Russia’s Security Council Nikolai Patrushev said in an interview that the Russian government “is not chasing deadlines.”

Defense Minister Sergei Shoigu, meanwhile, told a meeting of a Russia-led security alliance of former Soviet states that Moscow is deliberately slowing down its offensive to allow residents of encircled cities to evacuate — even though forces have repeatedly hit civilian targets.

As Kharkiv, Ukraine’s second largest city, recovers from weeks of weeks of relentless bombardments, residents formed long lines to receive rations of flour, pasta, sugar and others staples this week.

Galina Kolembed, the aid distribution center coordinator, told The Associated Press that more and more people are returning to the city after Russian forces withdrew to focus on the Donbas.

Kolembed said the center is providing food to over 1,000 people every day — a number that keeps growing. “Many of them have small kids, and they spend their money on the kids so they need some support with food,” she said.

Meanwhile, Kirill Stremousov, a Russian-installed official in Ukraine’s Kherson region, said the pro-Kremlin administration will ask Moscow to set up a military base there.

Stremousov has previously said the region would ask the Kremlin to make it part of Russia.

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Becatoros reported from Kramatorsk, Ukraine. Associated Press journalists Yuras Karmanau in Lviv, Andrea Rosa in Kharkiv, Danica Kirka in London and other AP staffers around the world contributed.

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