ANDRIIVKA, Ukraine (AP) — Ukraine gathered its dead and collected evidence of Russian atrocities on the ruined outskirts of Kyiv, as the two sides geared up Wednesday for what could become a climactic battle by Moscow’s forces to seize the country’s industrial east.

As the US and its Western allies moved to impose new sanctions against the Kremlin in retaliation for what they branded war crimes, Ukrainian President Volodymyr Zelenskyy said Russian forces were trying to push deep into Ukraine in the east, but the Ukrainian army was holding them back.

“The fate of our land and of our people is being decided. We know what we are fighting for. And we will do everything to win,” Zelenskyy said.

Ukrainian officials have stepped up calls for civilians to evacuate westward from towns near the front line ahead of the anticipated Russian offensive, and some essential services were being moved away. Local authorities in Sloviansk said postal and pension operations were clearing out and bank branches in town were shutting down.

A Western official, speaking on condition of anonymity to discuss intelligence, said it will take Russia as much as a month to regroup for a major push on eastern Ukraine. Almost a quarter of its battalion tactical groups in the country have been rendered “non-combat-effective” and have either withdrawn or merged with other units, the official said.

In the scarred and silent streets of Bucha and other towns around Ukraine’s capital where Russian forces withdrew over the past several days, investigators sought to document what appeared to be widespread killings of civilians. Some had evidently been shot at close range, while others were found with their hands bound or their flesh burned.

At a cemetery in Bucha, workers began to load more than 60 bodies apparently collected over the past day into a grocery shipping truck for transport to a facility for further investigation. A few of the black body bags were not fully closed. A glimpse showed the bloodied face of a young adult. Another revealed a pair of white sneakers.

More bodies were yet to be collected in Bucha, days after the Russian retreat. The Associated Press saw two in a house in a silent neighbourhood. From time to time there was the muffled boom of workers clearing the town of mines and other unexploded ordnance.

In Andriivka, a village about 60 kilometres (40 miles) west of Kyiv, two police officers from the nearby town of Makariv came Tuesday to identify a man whose body was in a field beside tank tracks. Officers found 20 bodies in the Makariv area, Captain Alla Pustova said.

Andriivka residents said the Russians arrived in early March and took locals’ phones. Some people were detained, then released; others met unknown fates. Some described sheltering for weeks in musty, cramped cellars normally used for storing vegetables for winter.

With the sixth week of the war drawing to a close, the soldiers were gone, and Russian armoured personnel carriers, a tank and other vehicles sat destroyed on both ends of the road running through the village. Several buildings were reduced to mounds of bricks and corrugated metal. Residents struggled without heat, electricity or cooking gas.

“First we were scared, now we are hysterical,” said Valentyna Klymenko, 64. She said she, her husband and two neighbours weathered the siege by sleeping on stacks of potatoes covered with a mattress and blankets. “We didn’t cry at first. Now we are crying.”

To the north of the village, in the town of Borodyanka, rescue workers combed through the rubble of apartment blocks, looking for bodies. Mine-disposal units worked nearby.

The Kremlin has insisted its troops have committed no war crimes, charging that the images out of Bucha were staged by the Ukrainians.

Thwarted in their efforts to take the capital and forced to withdraw, President Vladimir Putin’s troops, along with mercenaries, are now pouring into the Donbas, Ukraine’s mostly Russian-speaking industrial heartland in the east.

Overnight, Russian forces attacked a fuel depot and a factory in the Dnipropetrovsk region, just west of the Donbas, authorities said. In the Luhansk region, which is part of the Donbas, Russian shelling Wednesday set fire to at least 10 multi-storey buildings and a mall in the town of Sievierodonetsk, the regional governor reported. There was no immediate word on deaths or injuries.

Ukrainian forces have been fighting Russia-backed separatists in Luhansk and the other Donbas region, Donetsk, since 2014. Ahead of its February 24 invasion, Moscow recognised the regions as independent states.

Ukrainian authorities have said the bodies of at least 410 civilians have been found in towns around Kyiv, and Associated Press journalists in Bucha counted dozens of corpses in civilian clothes and interviewed Ukrainians who told of witnessing atrocities.

In a video address Tuesday to the UN Security Council, Zelenskyy said that civilians had been tortured, shot in the back of the head, thrown down wells, blown up with grenades in their apartments and crushed to death by tanks while in cars.

He said that those who gave the orders and those who carried them out should face war crimes charges in front of a Nuremberg-type tribunal.

In reaction to the alleged atrocities, the US announced sanctions against Putin’s two adult daughters and said it is toughening penalties against Russian banks. Britain banned investment in Russia and pledged to end its dependence on Russian coal and oil by the end of the year.

The European Union was also expected to take additional punitive measures, including an embargo on coal.

Elsewhere in Ukraine, the aid group Doctors without Borders said its staff witnessed an attack Monday on a cancer hospital in a residential district of the southern city of Mykolaiv. The group said it was the third known strike in recent days on a hospital in the port city, whose capture is key to giving Russia control of the Black Sea coast.

It said it had no overall death toll, but its team saw one body.

The group said it also saw numerous small holes in the ground, scattered over a large area, that suggested the use of cluster bombs. Russia has denied using cluster munitions in Ukraine. The use of such weapons against civilians can be a violation of international law.

Attacks on medical facilities are deemed war crimes, and Russia has been accused of striking such sites, including a maternity hospital in the besieged southern port city of Mariupol, which is part of the Donbas and has been the scene of some of the worst suffering of the war.

British defence officials said 160,000 people remained trapped by Russian airstrikes and heavy fighting in that city, without electricity, communication, medicine, heat or water.

A convoy accompanied by the Red Cross has been trying to get into Mariupol since Friday and got within 20 kilometres (12 miles), but the organisation said it was too dangerous to enter.

Negotiators from Russia and Ukraine have been discussing ways to end the fighting. Kremlin spokesman Dmitry Peskov said those talks continue despite the war crime allegations.