Some of the supporting walls of the three-story building gave way and a fire broke out.
Emergency situations ministry spokeswoman Veronika Smolskaya was quoted by Russian news agencies as saying seven people were injured and three may still be trapped under concrete after the blast in the small Moscow-area town of Pavlovskaya Sloboda.
The blaze engulfed several apartments but firefighters quickly brought it under control, she said.
Emergency officials trawled through the rubble in the hazy spring sunshine as shocked locals looked on.
David Mikael Taclino
Inyu Web Development and Design
Creative Writer
