It had been feared everyone inside had been killed, but the BBC reported authorities as saying the bomb shelter underneath the building had held up despite the massive blast.

Deputy Mayor Sergei Orlov said between 1,000 and 1,200 people had sought refuge in the theater.

And while the number of casualties is unclear, a local politician told the BBC that the basement where people were sheltering had withstood the bombing. “It looks like most of them have survived,” Dmytro Gurin said.

Ukrainian officials said their fate was still unknown because the entrance to the shelter had been buried under rubble.