As many as 300 people may have been killed in the bombing of a theatre in the besieged city of Mariupol, according to Ukrainian authorities.
Local officials citing witness accounts said up to 300 people are feared dead after a drama theatre where hundreds of people had been sheltering was struck by a powerful Russian air strike on March 16.
"From witnesses comes information that about 300 people died in the Mariupol Drama Theatre as a result of the bombing by a Russian plane," Mariupol city council said in a statement on Friday.
Ukrainian officials previously said about 130 people were rescued from the rubble and that the theatre basement, where many people were reportedly sheltering at the time of the bombardment, had withstood the attack.
The Ukrainian government said it was impossible to get an exact death toll because Mariupol was under almost constant bombardment from Russian forces.
Russia has denied bombing the theatre.
Attempts to arrange passage out of Mariupol
Meanwhile, authorities said Ukrainian forces were still in control of the besieged port city of Mariupol.
Ukraine's top security official, Oleksiy Danilov, said on Friday there would be no surrender to Russian forces.
The Governor of Ukraine's Donetsk region echoed the news when he spoke on national television on Friday.
Governor Pavlo Kyrylenko said about 65,000 people had so far fled the city in private vehicles or on foot, but official efforts to organise mass evacuations under temporary ceasefires had mostly failed.
Earlier, Ukrainian authorities said they were hoping some civilians who had been trapped in Mariupol would be able to leave in private cars on Friday.
Civilians trapped there have been sheltering in basements with little food, power or running water.
Those who manage to leave Mariupol will find buses awaiting in the nearby city of Berdyansk which will take them to the city of Zaporizhzhia, Deputy Prime Minister Iryna Vereshchuk said.
Efforts to evacuate as many residents as possible came as the death toll continued to rise, with reports of mass graves being dug to bury victims.
The head of the UN human rights team in Ukraine said monitors had received increasing information about mass graves, including one that appeared to hold 200 bodies.
"We have got increasing information on mass graves that are there," Matilda Bogner told journalists by video link from Ukraine, saying some of the evidence came from satellite images.
Ms Bogner said civilian deaths in Ukraine exceeded 1,035, adding that the UN team was probing what appeared to be indiscriminate attacks by both sides in the conflict.
Ukrainian troops take back eastern towns
Ukrainian troops are recapturing towns east of the capital Kyiv, and Russian forces who had been trying to seize the city are falling back on their overextended supply lines, according to British intelligence.
Battlelines around Kyiv have been all but frozen for weeks with Russian columns threatening Kyiv from the north-west and the east.
But in an intelligence update on Friday, Britain described a Ukrainian counter-offensive that had pushed the Russians far back.
"Ukrainian counter-attacks, and Russian forces falling back on overextended supply lines, has allowed Ukraine to reoccupy towns and defensive positions up to 35 kilometres east of Kyiv," the update said.
Russia refocusing on 'core efforts' in Donbas
The update said Ukrainian forces were also likely to try to push the Russians back on the other main axis threatening Kyiv from the north-west, while in the south, Russia could still be planning to attack the port of Odesa after abandoning efforts to take Mykolaiv.
In an announcement that appeared to indicate more limited goals, the Russian defence ministry said a first phase of its operation was mostly complete.
"The combat potential of the armed forces of Ukraine has been considerably reduced, which … makes it possible to focus our core efforts on achieving the main goal, the liberation of Donbas," Sergei Rudskoi, head of the Russian general staff's main operational directorate, said.
A senior diplomatic source in Moscow described the announcement as a possible prelude to a climbdown.
Shortly after the announcement, Ukraine's defence ministry said Russian forces had managed to create a partial land corridor to Crimea from territory in Ukraine's Donetsk region.
Meanwhile, Volodymyr Borysenko, Mayor of Boryspol, an eastern suburb where Kyiv's main airport is located, said 20,000 civilians had left the area, answering a call to clear out so Ukrainian troops could push the Russians further back.
Ukrainian forces recaptured a nearby village the previous day and would have pushed on but halted to avoid putting civilians in danger, he said.
The cities of Chernihiv, Kharkiv and Sumy in the east have also endured devastating bombardment.
Chernihiv was effectively surrounded by Russian forces, its Governor said.
In Kharkiv, officials said six people had been killed by the shelling of an aid distribution site.
Video showed a blast striking a car park where scores of people were queuing. Reuters was able to confirm it was filmed outside a supermarket in Kharkiv.
Reuters
