Twelve people were killed early Tuesday when a fire swept through a building at a market in Moscow, news reports said. The fire burned through a two-storey building next to a hangar on the grounds of Kachalovsky market in the south of the city at around 5 am (0100 GMT), Itar-Tass news agency reported. A total of 15 people could still be inside the building, that was used as a hostel by market workers, the report said, quoting an anonymous law enforcement source. "According to the preliminary information, the fire can be caused by malfunction of electric appliances or short circuit," the report quoted the source as saying.