Up to 1,000 may have been taking refuge underground at the time of the blast, which Ukraine blames on Russia.
Ukraine’s President Volodymyr Zelenskyy said that 130 people had been saved after the bombing of a theatre in the port city of Mariupol under Russian siege, but “hundreds” were still trapped in the rubble.
Ukraine accused Russia of hitting the theatre on Wednesday. It had been feared that up to 1,000 people may have been taking refuge underground at the time of the blast. Russia has denied responsibility for the attack.
“More than 130 people have been saved. But hundreds of Mariupol residents are still beneath the rubble,” Zelenskyy said in a video address on Facebook on Friday.
He promised to continue rescue operations in Mariupol “despite shelling” in the southern city that has suffered vast destruction.
“Despite the shelling, despite all the difficulties, we will continue the rescue work,” Zelenskyy added.
Earlier, Ukraine’s ombudswoman Lyudmyla Denisova said a bomb shelter underneath the Drama Theatre survived the impact and some “adults and children” had emerged alive but added there was still no information on more than 1,000 other people official figures suggest were sheltering there when the bomb fell.
The Ukrainian authorities have not confirmed the number of possible casualties.
Days before the apparent attack, satellite images shared by private company Maxar showed the word “DETI” – “children” in Russian – written on the ground on either side of the building.
Meanwhile, the Russian army on Friday said it was fighting in the city centre of Mariupol.
Zelenskyy said Western deliveries of weapons to Ukraine were arriving too slowly.
“We again remind certain Western leaders that it will be a moral defeat for them … if Ukraine does not receive advanced weapons,” he said.
He repeated calls for European ports to deny entry to all Russian ships and criticised some Western firms for not leaving Russia after it invaded Ukraine on February 24.
“All Western companies must leave the Russian market,” he said.