Nguyen Thanh Tung, vice director of the Hanoi police, said on Saturday police were aiming to charge suspects with safety violations.
Inspectors were particularly interested in the property’s landlord, investigators said, as well as the role local government managers might have played in overlooking safety regulations.
At 0:30 a.m. on Friday, the fire began at a house in a small alley off Trung Kinh Street, Cau Giay District. There were two blocks on the premises, with a courtyard yard spanning 55 m2 separating the two in the middle of the property. One block of two stories was used by the owner's family and the other of three stories was divided into 12 rooms for tenants.
The courtyard, where the fire started, was used by the landlord's son for selling and repairing motorcycles and electric bicycles.
Two people related to the landlord and 12 tenants died in the fire. Initial investigation suggested that more of them died of getting burned than suffocated.
Among the deceased, 11 were aged below 30, including a pair of newlyweds. The youngest victim was 23 years old, and the oldest 62.
Among the six injured, one is in critical conditions.
Municipal authorities are now requesting that local district authorities inspect all rooms for rent in the city, and issue reports on the results of the inspections to higher authorities by June 15.
Last September, a fire at an alley house for tenants in Khuong Dinh Ward of Hanoi's Thanh Xuan District killed 56 people. The cause was determined to be a short circuit in a motorbike in the first-floor parking lot.
The owner of the house, which had been turned into mini apartments for rent, was arrested the next day. Former chairman of Khuong Dinh Ward and five police officers and construction officials were put under probe four months later for negligence.