Russian officials say at least 23 people were killed when a suspected gas explosion ripped through an apartment building early Tuesday.
About 20 more people are believed to still be trapped in the rubble of the building in the northern city of Arkhangelsk, about 1,000 kilometers north of Moscow. Three children are among the dead.
Authorities say they are searching for two men who may have stolen valves from the piping, allowing the gas to escape. Valves were also reported missing from nearby residences.
The Associated Press says the men may have wanted to sell the brass lids on the valves.
Officials say the explosion came at a time when most of the residents would have been asleep. The powerful blast leveled part of the building and shattered windows in nearby structures.
Moscow has sent rescue teams and equipment to help in the search efforts.