Thirty-two people were injured and most of them were hospitalized, emergency officials said.
The victims were municipal and market workers, and Mayor Yuri Luzhkov said all the dead were guest workers from outside Moscow. Mr Luzhkov added that  terrorism was unlikely.

Rescue workers used metal cutters and hydraulic lifters to clear the ruins of steel and concrete pieces. Workers used pickaxes to cut holes in the wreckage and knelt to call into the holes in search of survivors.

No sounds could be heard from beneath the rubble though sniffer dogs indicated there were still survivors there, Emergency Situations Ministry spokesman Viktor Beltsov said.

Investigators were looking at three possible causes of the collapse: improper maintenance of the building, a build up of snow and errors in the building's design, Moscow prosecutor Anatoly Zuyev said.

CNN