Ukraine's president showed a harrowing video of dead civilians to the UN Security Council Tuesday and called for "accountability" for apparent Russian atrocities, as fears grow that Moscow is preparing new offensives.

With global revulsion solidifying over civilian killings in the town of Bucha, President Volodymyr Zelensky likened Russia's assault to Nazi war crimes and Western nations ramped up sanctions against the Kremlin.

The United States is expected Wednesday to ban all new investment in Russia, while Britain announced it has frozen some $350 billion in assets from President Vladimir Putin's "war chest" so far.

Despite the pressure, bombardments rocked the Kyiv area villages of Velyka Dymerka and Bogdanivka, where 12 people were killed by Russian firearms and artillery, Ukraine's prosecutor general's office said on Telegram.

The scale of devastation in Borodianka was overwhelming, with buildings flayed open
The scale of devastation in Borodianka was overwhelming, with buildings flayed open AFP / Sergei SUPINSKY

And new warnings emerged from Ukraine that other shattered communities, notably the town of Borodianka, may have suffered even worse fates than Bucha.

Zelensky, in an impassioned speech by videolink from Kyiv to the 15-member Security Council, demanded stronger action as he delivered a chilling account of Putin's six-week-old war.

People "were killed in their apartments, houses... civilians were crushed by tanks while sitting in their cars in the middle of the road," Zelensky said.

"They cut off limbs, slashed their throats, women were raped and killed in front of their children."

Zelensky has denounced 'war crimes' and attempted 'genocide' while appealing for new sanctions and more Western weapons
Zelensky has denounced 'war crimes' and attempted 'genocide' while appealing for new sanctions and more Western weapons AFP / RONALDO SCHEMIDT

"Accountability must be inevitable," he added, calling for Russia's exclusion from the Security Council -- on which it holds veto power.

"Are you ready to close the UN" and abandon international law, the president asked. "If your answer is no, then you need to act immediately."

Zelensky's plea follows the harrowing discovery of civilian victims in Bucha and other towns near Kyiv following Russian troop withdrawals, which he and other officials have denounced as war crimes and attempted genocide.

Russian invasion of Ukraine
Russian invasion of Ukraine AFP / Sophie RAMIS

In a subsequent address to Spanish lawmakers, Zelensky compared Russia's devastating assault to the Nazis' 1937 bombing of the town of Guernica.

During a grim cleanup Tuesday in Bucha, local workers placed the remains of partially burned bodies into black bags and lifted them into a van.

After touring the devastation, Interior Minister Denys Monastyrsky told journalists that "dozens of bodies" remain in Bucha apartments and in nearby woods.

"What we've seen in Bucha is not the random act of a rogue unit. It's a deliberate campaign to kill, to torture, to rape, to commit atrocities," US Secretary of State Antony Blinken said.

Europe's worst conflict in decades has killed as many as 20,000 people, according to Ukrainian estimates
Europe's worst conflict in decades has killed as many as 20,000 people, according to Ukrainian estimates AFP / Sergei SUPINSKY

Looking ahead, NATO chief Jens Stoltenberg said the alliance expects a Russian push in "coming weeks" to try to seize Ukraine's entire eastern region of Donbas, and create a land bridge to occupied Crimea.

Both Washington and the EU have vowed to squeeze Russia's economy until Putin is forced to halt the war he launched.

European Commission chief Ursula von der Leyen, who said she would travel to Kyiv this week, has offered the bloc's assistance in documenting proof of war crimes.

The Kremlin has denied any civilian killings, claiming the images emerging from Bucha and other sites are fakes produced by Ukrainian forces, or that the deaths occurred after Russian soldiers pulled out.

Volodymyr Zelensky addresses the United Nations Security Council
Volodymyr Zelensky addresses the United Nations Security Council AFP / TIMOTHY A. CLARY

But one Bucha resident named Olena told AFP she saw Russian soldiers shoot a man in cold blood after "brutal" troop units moved in.

"Right in front of my eyes, they fired on a man who was going to get food at the supermarket," said the 43-year-old, who did not wish to give her family name.

Despite Olena's and other firsthand accounts, Moscow's UN ambassador Vassily Nebenzia rejected Zelensky's claims of Russian atrocities, telling the Security Council that the "ungrounded accusations... are not confirmed by any eye witnesses."

Zelensky delivered a forceful rebuttal, airing a graphic, 90-second video of what he said were images from towns including Bucha, Irpin, Dymerka, and the besieged southern port of Mariupol.

City workers carry bags with six partially burnt bodies in the town of Bucha, where Ukrainian officials accuse Russian forces of carrying out war crimes against civilians
City workers carry bags with six partially burnt bodies in the town of Bucha, where Ukrainian officials accuse Russian forces of carrying out war crimes against civilians AFP / Genya SAVILOV

The footage showed partially uncovered dead people, including children, in shallow graves, bodies in a courtyard, burned corpses in the streets, and slumped victims with hands tied behind their back.

In the push to isolate Moscow, Spain, Italy, Denmark and Slovenia expelled dozens of its diplomats suspected of being intelligence operatives, after France and Germany did the same Monday, for a total of some 180 expulsions in 48 hours.

The Kremlin called it a "short-sighted move" that would complicate efforts to negotiate an end to the hostilities.

Putin warned of "reprisals" for recent European measures targeting Russian gas giant Gazprom -- and said Moscow would "monitor" its food exports to "hostile" nations, raising the spectre of further inflation surges worldwide.

Europe's worst conflict in decades has killed as many as 20,000 people, according to Ukrainian estimates, and 4.25 million have fled the country.

Many in Ukraine are bracing for further Russian bombardments.

Ukrainian officials say over 400 civilian bodies have been recovered from the wider Kyiv region, many buried in mass graves.

But Zelensky said he had information of worse atrocities in places such as Borodianka.

"Bucha is not the worst," Ukrainian presidential advisor Oleksiy Arestovych said on a Russian lawyer's YouTube channel. "Everyone who managed to visit Borodianka says that it is much, much worse."

AFP reporters who briefly visited the Borodianka area saw no bodies in the streets, but locals reported many deaths, and buildings were ravaged and blown open.

"I know five civilians were killed," said 58-year-old Rafik Azimov. "But we don't know how many more are left in the basements of the ruined buildings after the bombardments."

"I buried six people," another resident, Volodymyr Nahornyi, said. "More people are under the ruins."

Foreign Minister Sergei Lavrov meanwhile said Tuesday on Russian television that Russia was "ready" to continue the negotiations.

Ukraine has proposed an international agreement with other countries guaranteeing its security in return for accepting a neutral and non-nuclear status, not joining NATO and refusing to host foreign military bases.

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