All were citizens of former Soviet nations in Central Asia, spokesman Sergei Vlasov said.
Several million migrants from Tajikistan, Uzbekistan and Kyrgyzstan have come to Moscow in search of work. Many of them have found jobs in construction or at the city’s sprawling markets, which sell everything from clothes to construction materials.
Vlasov said the fire that broke out at the Kachalovsky market at 5 a.m. Tuesday tore through an insulated metal shed where the workers slept on bunk beds. The roof collapsed during the blaze, he said.
Investigators were still determining the cause of the fire, but said they suspected it may have started with electric heaters. A light snow fell overnight.
Sergei Gorbunov, the chief of the fire department in Moscow’s southeast district, said on Russian television that the workers were unable to exit through the one door connecting their living quarters with an adjacent storage hangar. He did not say why.
Video aired on television showed that the windows of the blue metal shed were barred and firefighters had pulled away strips of metal sheeting from one wall.