In interviews, residents and local officials in Mariupol, a port on the Sea of Azov, described nightmarish conditions after five days of shelling by Russian forces around the city. On Sunday, city officials said they would attempt to resume an evacuation effort that was called off a day earlier because of Russian attacks.

“There’s no electricity, no heating, no telephone connection. It is absolute horror,” said Petro Andryushchenko, an adviser to the mayor of Mariupol. “People drink from puddles in the streets.”

The shelling has destroyed the city’s left bank district, he said, making it “unfit for human life.” The city had not been able to accurately count the dead or even help many of the wounded because of the barrage, he added.

“It just never stops,” he said. “Everyone who tries to go outside risks their life. That is why the mayor can’t ask people to do that, it would be like sending people to a certain death.”