Hundreds gathered outside a morgue in western Hanoi Wednesday, waiting to hear if their families and friends were victims of a devastating apartment fire that killed more than 50 people.

The fire in the 10-storey building, which had only one exit and wire-barred balconies, started as residents fell asleep on Tuesday night.

Neighbours and residents of the building in the capital's southwest said they heard screaming as people struggled to escape the flames and thick smoke.

Police said 56 people were killed and 37 injured, while state media reported that three children were among the dead.

At the morgue in a military-owned hospital, officials appeared at the entrance every half hour to announce through a loudspeaker that there was another victim for families to identify.

Holding out a photo on a mobile phone or simply describing the dead, medical workers asked desperate relatives if they recognised their loved ones.

Cries broke out each time a match was found.

Authorities tried to prevent families talking to journalists, but one man, who did not give his name, said his daughter had died and feared his wife had also perished.

"I lost my daughter, who was staying with her mother," he said through tears.

Unsure where his wife was, he told AFP: "I guess she did not make it either."

One group of five women, sitting on the floor outside the morgue, said their "whole family had gone".

"They were our children and grandchildren," they said.

'So much suffering' 

Elsewhere in the morgue, families who knew their loved ones had died sat waiting for hours to collect the bodies.

One man, who gave his name as Dung, said his two young cousins, a man and a woman, were among the dead. They had come from their home in nearby coastal Thai Binh province to study.

"They were at university here. Our family bought them this small apartment.

"We are waiting here to bring back them back to our home province for burial, but we don't know when they are going to release the body."

State media reported that Hanoi would provide around $1,500 to families for each adult who had died. Compensation would also be given for those who had lost a child.

The apartment block, which is down a narrow alley in a residential area of the capital, was home to several young families. Many had come from other provinces to work or to study.

Around 150 people lived in the building, which had no emergency ladder on the outside.

Survivor Tran Thi Lien, 65, who bought her second-floor apartment in the block eight years ago, told AFP that residents had requested better fire safety equipment many times.

"They still did not do it," she said.

"When people die like this… it causes so much suffering."