A gas explosion ripped through the upper floors of a nine-story apartment building in the Moscow region Monday, killing at least four people and injuring six others, the Emergency Situations Ministry said.
The explosion, which occurred at about 9:30 a.m. in the village of Zagorskiye Dali near Sergiev Posad, caused a partial collapse of four apartments between the eighth and ninth floors of the building. A total of eight apartments occupied by 27 people were damaged by the blast, RIA Novosti reported.
News reports said late Monday that up to three more people were located under debris from the explosion. It was unclear whether they were suspected still to be alive.
Investigators are currently analyzing fragments of the gas system to determine the cause of the explosion. A criminal case has been opened under Article 219 of the Criminal Code, which covers "violations of fire safety requirements resulting in death."
Among the victims of the blast was a six-month-old baby, along with his mother and grandparents who shared the same apartment.
Deadly household gas explosions are not uncommon in Russia. According to RIA Novosti, there have been ten separate gas explosions that resulted in death since the start of the year. Thirteen such incidents occurred in 2012, according to the news agency.