A fire engulfed a residential building in the densely populated Mongkok district in Hong Kong Wednesday, killing nine people and injuring 30 others.

According to reports, the fire broke out in the early hours of Wednesday morning in hawker's stalls and spread to a nearby residential block. Officials confirmed that while the cause of the fire was unknown, an investigation was under way.

Local television showed firemen pulling shaken survivors and body bags from rooftops, while badly burnt victims were wrapped in bandages and sent to hospital. Firefighters eventually brought the fire under control, more than eight hours after it began.

In a similar incident, last year 50 stalls burned to the ground in the same street, injuring six people. Wednesday's fire is the most serious in recent years in Hong Kong, one of the world's most densely populated cities. Fires in high rise blocks are a recurring concern for the city's administrators.

Hong Kong Chief Executive Donald Tsang and senior city officials visited the injured at hospitals. Acting Home Affairs Secretary Florence Hui stated the government had set up three help-desks for affected residents and have opened the Boundary Street Sports Centre for them.