The Emergency Situations Ministry says the blast in the town of Pavshino, five kilometers outside Moscow, was probably caused by a buildup of explosive gases.
A ministry spokeswoman, Natalia Lukash, ruled out terrorism.
The explosion caused the roof of the three-story structure to cave in, shattered windows in nearby houses, and damaged some roofs.
It also left Pavshino and a number of nearby towns and villages without water.
(ITAR-TASS, AP, RIA Novosti, Interfax)