A fire in a nine-storey apartment building in Vietnam’s capital has killed at least 56 people, including at least four children, while 37 more are being treated, state media reported citing the police.

Of the 56 people confirmed dead, the police have identified 39 victims, the state-owned Viet Nam News said.

Initial reports about the death toll were unclear since the injured and dead were taken to different hospitals across the city.

The fire started around midnight and was extinguished in the morning. Rescue operations continued throughout the day.

The police have detained the owner of the building as part of their investigation.

State-owned national television channel VTV said four children were among those killed.

The fire was believed to have started late Tuesday and rescuers struggled to reach the building on a narrow lane in south Hanoi.

It was home to 150 residents, and 54 of the 70 people rescued from the fire were taken to hospital for their injuries, state media said.

Residents were being treated for smoke inhalation and injuries sustained as they tried to escape the building.

Authorities were investigating the cause of the fire, which started around midnight in the parking area of the building that had no emergency exit.