Rescuers in northern Russia say their hopes of finding any more survivors in the debris of a nine-storey block of flats are fading fast.
The rest of the building could come down crushing soon
A suspected gas blast wrecked part of the building in Archangel before dawn on Tuesday, killing at least 43 people.
At least another dozen could be trapped in the debris, but rescuers said the rest of the block could collapse soon.
Police are looking for two men who allegedly stole bronze fittings of the block's gas pipes to sell for scrap.
The prosecutor-general's office said a gas explosion was "the most likely cause" of the blast.
Gas leak explosions occur frequently in Russia, where local authorities struggle to find funds to repair the crumbling Soviet-era infrastructure.
Tenants at the blast scene reported seeing two homeless men carrying metal pipes and tools from the building on the night of the explosion.
Local officials also said gas valve parts were found missing in two neighbouring buildings on the same night, but the leaks were capped in time.
Andrei Seleznyov, 52, a resident of a neighboring
building, said homeless men had been systematically
stealing valve lids in the past.
"These damned vagabonds unscrewed these valves a hundred times in the past, but then it didn't lead to explosions," he was quoted as saying by the AP news agency.
Hundreds of rescuers worked through the night in a pile of rubble three storeys high, removing broken metal, crushed furniture and slabs of concrete.
So far 24 people, including two children, have been pulled out alive. Seven of those who died were also children.
No one knew the exact figure for those who might be still trapped under the rubble.
"Unfortunately, it is unlikely that survivors will be found," Emergencies Ministry official Yury Vorobyov said.
"But there is always hope."
Rescue teams are concentrating their efforts on trying to reinforce a wall to prevent it from collapsing.