KYIV, Ukraine (AP) Rescue workers searched for survivors Thursday in the ruins of a theater blown apart by a Russian airstrike in the besieged city of Mariupol , while scores of Ukrainians across the country were killed in ferocious urban attacks on a school, a hostel and other sites.

Hundreds of civilians had been taking shelter in the grand, columned theater in central Mariupol after their homes were destroyed in three weeks of fighting in the southern port city of 430,000.

More than a day after the airstrike, there were no reports of deaths. With communications disrupted across the city and movement difficult because of shelling and other fighting, there were conflicting reports on whether anyone had emerged from the rubble.

We hope and we think that some people who stayed in the shelter under the theater could survive, Petro Andrushchenko, an official with the mayors office, told The Associated Press. He said the building had a relatively modern basement bomb shelter designed to withstand airstrikes. Video and photos provided by the Ukrainian military showed that the at least three-story building had been reduced to a roofless shell, with some exterior walls collapsed.

Other officials had said earlier that some people had gotten out. Ukraines ombudswoman, Ludmyla Denisova, said on the Telegram messaging app that the shelter had held up.

Satellite imagery on Monday from Maxar Technologies showed huge white letters on the pavement in front of and behind the theater spelling out CHILDREN in Russian DETI to alert warplanes to those inside.

Across the city, snow flurries fell around the skeletons of burned, windowless and shrapnel-scarred apartment buildings as smoke rose above the skyline.

We are trying to survive somehow, said one Mariupol resident, who gave only her first name, Elena. My child is hungry. I dont know what to give him to eat.

She had been trying to call her mother, who was in a town 50 miles (80 kilometers) away. I cant tell her I am alive, you understand. There is no connection, just nothing, she said.

Cars, some with the Z symbol of the Russian invasion force in their windows, drove past stacks of ammunition boxes and artillery shells in a neighborhood controlled by Russian-backed separatists.

Russias military denied bombing the theater or anyplace else in Mariupol on Wednesday.