Ambulances rushed the injured to nearby hospitals as firefighters battled to put out the blaze, which started before dawn at a stall in the Ladies Market in the Mong Kok area of Kowloon.

"Nine people died and 30 people have been sent to hospital for treatment so far," an emergency services spokeswoman said.

The narrow market street was a wall of flame and thick black smoke as the fire tore through the flimsy stalls and residential flats above, witnesses said.

Local television showed firemen pulling shaken survivors and body bags from rooftops, while badly burnt victims were wrapped in bandages and sent to hospital.

The cause of the fire was not known and an investigation was under way, officials said.

A suspected arson attack destroyed dozens of stalls in the same market last year, but police would not comment on what might have triggered the latest fire.

The blaze broke out at a street hawker's booth around 4:40 am and quickly spread through the residential building, a government spokesman said.

She said eight "charred bodies" were found at the site. Officials later increased the toll to nine.

A hotline had been set up to help people search for missing or injured loved ones.

A local resident said the building where many of the victims lived had been subdivided into small living spaces known as cubicles or cage homes.

A fire at a subdivided apartment building in Kowloon killed four people earlier this year, prompting calls from some lawmakers for a ban on cubicle flats.

Chief Executive Donald Tsang rejected the calls, acknowledging that rocketing apartment prices left many people with no option but to live in overcrowded, unsafe buildings.

"Undoubtedly 'sub-divided units' pose risks for building safety, but they do provide accommodation for low-income people not eligible for public housing," he said in an October policy address.