It’s feared as many as 60 villagers remain buried beneath the burnt rubble of a school that was bombed by the Russians and burst into flames which took hours to put out.

The school in the town of Bilohorivka, in the Luhansk region, was being used as a shelter, with local officials saying as many as 90 people had been hiding in the basement.

Around 30 had been rescued according to reports on Monday morning Australian time but 60 remained unaccounted for.

Much of Luhansk, in Ukraine’s east, is in the Donbas region where Russia has focused is military attacks in recent weeks after pulling out of the capital Kyiv and the north.

Governor Serhiy Gaidai said a Russian plane dropped a bomb on the school on Saturday afternoon (local time), causing a fire that engulfed the building.

“The fire was extinguished after nearly four hours, then the rubble was cleared, and, unfortunately, the bodies of two people were found,” Gaidai wrote on the Telegram messaging app.

“Thirty people were evacuated from the rubble, seven of whom were injured. Sixty people were likely to have died under the rubble of buildings.”

Reuters could not immediately verify the report.

Ukrainian soldiers vow not to surrender as Russia resumes shelling of the Azovstal steel plant. Photo: AAP

In the ruined southeastern port city of Mariupol, Ukraine’s remaining soldiers in the Azovstal plant have vowed to fight to the death after the civilians who had been hiding there for months were finally evacuated.

Russia has reportedly resumed its bombardment of the steelworks, but members of Ukraine’s battalion said during a live press conference they would not give in.

“Surrender for us is unacceptable because we can’t grant such a big gift to the enemy,” said Lt Illia Samoilenko.

“We are basically dead men. Most of us know this. It’s why we fight so fearlessly.”

Scores of scores of civilians were evacuated on Sunday morning (Australian time) in an operation brokered by the United Nations and the International Committee of the Red Cross.

Ukrainian President Volodymyr Zelensky said more than 300 civilians had been rescued over the week and authorities would now focus on trying to evacuate the wounded and medics. Other Ukrainian sources have cited different figures.

Meanwhile Mr Zelensky has met G7 world leaders in online talks ahead of Victory in Europe Day which marks Nazi Germany’s surrender in 1945.

Canadian Prime Minister Justin Trudeau made a surprise visit to Ukraine on Sunday, touring the northern town of Irpin and saying he was shocked by the damage he saw at civilian homes.

Jill Biden also made an unannounced visit on Sunday, holding a surprise Mother’s Day meeting in western Ukraine with first lady Olena Zelenska.

“I wanted to come on Mother’s Day,” the US first lady said.

Putin brings ‘shame’ on Russia

A statement released after the G7 meeting accused Vladimir Putin of bringing “shame” on Russia and his people’s historic sacrifices.

The strong condemnation was intended as a rallying call ahead of Moscow’s own Victory Day parade on May 9 in which it traditionally celebrates Nazi Germany’s defeat in 1945 with huge military parades.

“Through its invasion of and actions in Ukraine since 2014, Russia has violated the international rules-based order, particularly the UN charter, conceived after the second world war to spare successive generations from the scourge of war,” read the statement.

“President Putin and his regime now chose to invade Ukraine in an unprovoked war of aggression against a sovereign country.

“His actions bring shame on Russia and the historic sacrifices of its people.”

G7 heads pledged to phase out or ban the import of Russian oil which would “hit hard at the main artery of Putin’s economy and deny him the revenue he needs to fund his war”.

“We will ensure that we do so in a timely and orderly fashion, and in ways that provide time for the world to secure alternative supplies,” they added.

Casting a look back at World War II, the leaders stressed unity in their resolve that Putin must not win.

“We owe it to the memory of all those who fought for freedom in the Second World War, to continue fighting for it today, for the people of Ukraine, Europe and the global community,” they said.

The G7 countries include the US, UK, Canada, Germany, France and Italy and Japan.

The US also announced new sanctions against Russia for its invasion of Ukraine.

They include cutting off Western advertising from Russia’s three biggest television stations, banning US accounting and consulting firms from providing services to any Russian, and new restrictions on Russia’s industrial sector, including cutting off Moscow from wood products, industrial engines, boilers, bulldozers and more.

Mr Putin is expected to talk about what it calls its special military operation in Ukraine and address troops on Red Square on Monday.

Bono’s ‘freedom’ concert in Kyiv

Irish rock group U2’s frontman Bono and his bandmate The Edge performed a 40-minute concert in a metro station in the Ukrainian capital of Kyiv and praised Ukrainians fighting for their freedom from Russia.

“Your president leads the world in the cause of freedom right now … The people of Ukraine are not just fighting for your own freedom, you’re fighting for all of us who love freedom,” Bono told a crowd of up to 100 gathered inside the Khreshchatyk metro station.

Bono rallied the crowd between songs which included Sunday Bloody Sunday, Desire and With or Without You.

“This evening, 8th of May, shots will ring out in the Ukraine sky, but you’ll be free at last. They can take your lives, but they can never take your pride,” he said.

Russia invaded Ukraine on February 24, pressing towards Kyiv before withdrawing its forces from near the capital at the end of March to concentrate its firepower on eastern Ukraine.

-with AAP