Many people were feared dead and several injured in a fire at a nine-story apartment block in Vietnam's capital of Hanoi, the official news agency said on Wednesday, while authorities have yet to confirm the number of deaths.

The fire broke out in the middle of the night in the building with 150 residents, the official Vietnam News Agency (VNA) said, but had been contained by 2 a.m. local time.

Television images showed firefighters equipped with hoses and ladders at the scene by night while a column of thick, dark smoke billowed from the building during the day.

Police have launched an investigation into the cause of the fire, the agency said.