Rescue workers on Thursday dug survivors out of the rubble of a theatre in the besieged city of Mariupol which Ukraine said had been hit by a Russian air strike as people sheltered there from bombardments.
Russia denied striking the theatre. But Ukraine's capital Kyiv came under renewed Russian shelling on Thursday as the war entered its fourth week. Western sources and Ukrainian officials said Russia's assault had stalled.
Officials from both sides meanwhile met again for peace talks, but they said their positions remained far apart.
Mariupol, a southern port city, has suffered the worst humanitarian catastrophe of the war, with hundreds of thousands of civilians trapped in basements with no food, water or power as Russian forces pound it with artillery fire and air strikes.
City authorities said they were still not able to estimate the number of possible casualties from Wednesday's alleged air strike on the theatre.
"Yesterday and today, despite continuous shelling, rubble is being cleared as much as is possible and people are being rescued. Information about victims is still being clarified," the city council said in a statement. It provided no figures on the numbers rescued.
Commercial satellite pictures showed the word "children" had been marked out on the ground in front of the building before it was hit.
Russian foreign ministry spokeswoman Maria Zakharova said the allegation that Russia had bombed the theatre was a "lie".