The explosion occurred on sewage lift station No.1 in the Krasnogorsk district of the Moscow Region at 9.10 Moscow time (5.10 a.m. GMT). The three-story brick facility fully collapsed. Water supplies to some local residents were partly disrupted.
"According to data at 11.45 Moscow time, one person was pronounced dead," a ministry source said. "Five people were taken to the hospital."
The source said paramedics rendered medical assistance to another two injured persons.
Earlier, Russia's emergencies services said two were killed and 12 injured in the explosion.