An explosion ripped through a sewage plant in a town outside Moscow on Saturday, killing two people, injuring 12 and leaving one missing, the Emergency Situations Ministry said.
Authorities said the blast in the town of Pavshino, about 5 kilometers (3 miles) beyond Moscow's western periphery, likely was caused by a build-up of explosive gases.
Emergency Situations Ministry spokeswoman Natalia Lukash said officials ruled out terrorism.
The powerful explosion caused the roof of the three-story structure to cave in, shattered windows in nearby houses, damaged some roofs and left Pavshino and nearby towns and villages without water. Local residents quickly emptied local stores' supplies of drinking water and spent hours in lines to water wells to get some more.
Four people who lived in temporary housing near the sewage plant were hospitalised along with the injured shift worker, while others had more minor injuries.