Sixteen people have been confirmed dead since a fire engulfed a printing office warehouse in the northeast of Moscow, the Emergency Ministry said. One of the victims sent to hospital has died there, the Moscow mayor said.

“As the fire was being extinguished, the staff found a room cut off by the fire,” the press service of the Emergencies Ministry for the Moscow region told TASS.

“Fire-fighters broke through the wall and found 16 bodies there,” it said.

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Moscow authorities and law enforcement officials will look into the cause of the blaze, Moscow Mayor Sergey Sobyanin promised in a post on Twitter.

“А fire occurred on Altyevskoye highway. Unfortunately, there are a lot of victims. We’ll be investigating with the law enforcement bodies.”

The Emergencies Ministry has reported that twelve people were rescued from the fire.

According to preliminary version, all victims died in their sleep, due to inhaling toxic fumes from the fire, according to a source cited by RIA Novosti news agency.

One of the victims sent to hospital has died there, Moscow mayor Sergey Sobyanin posted on Twitter.

Moscow officials said all of the fire victims were from Kyrgyztan, a country located in Central Asia that used to be one of the Soviet republics.

The fire began during a shift change, so the victims weren’t sleeping, as was reported earlier, but had, rather, arrived early in the morning, according to a law enforcement source quoted by TASS news agency.

The blaze was reportedly ignited by a lamp in a loading area.

“We couldn’t save some of the workers because they went to a remote room from which you can’t escape, and died inhaling combustion gases,” vice head of the Moscow Emergencies Ministry, Leonid Belyayev, told TASS.

Another source in the Emergencies Ministry told Interfax that the victims may actually have gotten lost in the building due to the smoky conditions while trying to escape.