Twelve people, including three children, have died after a fire swept through a textile workshop in northeastern Moscow on January 30, causing the roof to collapse.
Arson and negligence are being considered as possible causes of the fire, according to Russia's Investigative Committee.
The country's human rights ombudsman said three children were among the dead and that the victims were migrant workers. Interfax cited a source in the Emergency Services Ministry as saying the migrants were from Central Asia.
The blaze covered an area of 3,000 square meters and took about five hours for firefighters to extinguish.