MOSCOW, Jan. 27 (Xinhua) -- Four people were killed and six others injured in a fire early Tuesday at a hostel in the city of Balashikha, the Moscow region, said local authorities.

According to the Moscow regional investigative committee, the blaze occurred in a privately owned three-story building, originating from the second floor and spreading across about 35 square meters.

Firefighters discovered the bodies of two men and two women, said the committee, adding that among the six injured were two children and a 15-year-old teenager.

Preliminary findings suggest the fire may have been caused by careless handling of fire. Investigators have opened a criminal case on charges of causing deaths by negligence, because the building may have been illegally rented out for accommodation.