As many as 60 people were feared to have been killed in the Russian bombing of a village school in the eastern Ukrainian region of Luhansk, the regional governor said on Sunday.
Governor Serhiy Gaidai said Russian forces dropped a bomb on Saturday afternoon on the school in Bilohorivka where about 90 people were sheltering, 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 persons were found," Mr. 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.
Ukraine and its western allies have accused the Russian forces of targeting civilians in the war, which Moscow denies.
Meanwhile, U.S. President Joe Biden met with his G7 counterparts and Ukrainian President Volodymyr Zelensky on Sunday to discuss Russia's war in Ukraine and new measures to punish Moscow.
Mr. Biden, who has lauded unity among the Group of Seven large economies in standing up to Russian President Vladimir Putin, was scheduled to meet by video conference with his fellow leaders from his home in Delaware, where he is spending the weekend.
The White House said the leaders would discuss adding to the sanctions that the western countries have imposed on Russia since its February 24 invasion.
"They will discuss the latest developments in Russia's war against Ukraine; the global impact of Mr. Putin's war; showing support for Ukraine and Ukraine's future; and demonstrating continued G7 unity in our collective response, including building on our unprecedented sanctions to impose severe costs for Mr. Putin's war," the White House said in a statement.
The meeting comes ahead of Russia's Victory Day celebrations on Monday. Mr. Putin calls the invasion a "special military operation" to disarm Ukraine and rid it of anti-Russian nationalism fomented by the West. Ukraine and its allies say Russia launched an unprovoked war.
In the ruined southeastern port city of Mariupol, scores of civilians have been evacuated from a sprawling steel plant in a week-long operation brokered by the United Nations and the International Committee of the Red Cross (ICRC).
Mr. Zelensky said in an address late on Saturday that more than 300 civilians had been rescued from the Azovstal steelworks and authorities would now focus on trying to evacuate the wounded and medics. Other Ukrainian sources have cited different figures.
Russian-backed separatists on Saturday reported a total of 176 civilians evacuated from the plant.
In an emotional address on Sunday for Victory Day, when Europe commemorates the formal surrender of Germany to the Allies in World War Two, Mr. Zelensky said evil had returned to Ukraine with the Russian invasion, but his country would prevail.
Underlining Western support for Ukraine, Britain pledged to provide a further 1.3 billion pounds ($1.6 billion) in military support and aid, double its previous spending commitments.
Victory Day is a major event in Russia and Mr. Putin will preside on Monday over a parade in Moscow's Red Square of troops, tanks, rockets and intercontinental ballistic missiles, showing military might even as his forces fight on in Ukraine.
His speech could offer clues on the future of the war. Russia's efforts have been stymied by logistical and equipment problems and high casualties in the face of fierce resistance.
U.S. Central Intelligence Agency Director William Burns said on Saturday that Mr. Putin was convinced "doubling down" on the conflict would improve the outcome for Russia.
"He's in a frame of mind in which he doesn't believe he can afford to lose," Mr. Burns told a Financial Times event in Washington on Saturday.
G7 agrees to intensify economic pressure on Putin: Johnson
G7 leaders agreed that the world must intensify economic pressure on Russia’s President Vladimir Putin in any way possible, British Prime Minister Boris Johnson’s office said on Sunday after he addressed the group.
Mr. Johnson said “the world must go further and faster to support Ukraine,” his office said after the call, which also included Ukraine’s President Volodymyr Zelensky.
“Ukraine needed to receive military equipment that allowed them to not just hold ground in Ukraine, but recapture it,” Mr. Johnson told the leaders, according to his office.