The blaze that broke out at the residential complex in Hong Kong's Tai Po district on Wednesday afternoon killed at least 128 people, gutting seven of its eight high-rise towers and the almost 2,000 apartments they contained.

Chan, 39, told AFP on Saturday he "couldn't sleep every night" after the tragedy.

Dozens of people remain in hospital, with some still in critical condition, and many more are still missing.

"We feel so small, and there aren't many things we could do," Chan said.

"I hope the government can investigate thoroughly, so the deaths can be accounted for."

Many Hong Kongers spend their entire lives striving to buy a flat in the financial hub, where property prices are sky-high, Chan said.

The blaze destroyed years of effort made by thousands of people within hours.

Sobbing could be heard along the queue of mourners that stretched for hundreds of metres on Saturday.

The city's government announced a three-day mourning period on Friday night, and thousands brought their families to the estate to pay their respects.

Mourners gathered at a fire cordon to lay flowers, some staring blankly at the burned-out buildings.

Many of the bouquets left there contained handwritten notes with the words "Rest In Peace".

Lincoln Lam, a 29-year-old art educator, tearfully told AFP he wanted "to express grief for the victims" and hoped to bring a spirit of mutual support during such a difficult time.

People were still arriving to pay their respects as dusk descended.

A woman surnamed Ng, in her 50s, paused and then told AFP her nephew owns a unit at the complex but has no clue what is left.

"The only thing they can do is to stay positive for the future, (they have been) figuring out how to rebuild their homes and handle all the follow-up procedures," Ng said.

"(The government) must establish an independent commission of inquiry," she said, adding that it must be done urgently and thoroughly and that the public be given trustworthy information.

The Chinese city's anti-corruption watchdog originally arrested eight people over the blaze, and then arrested another three on Saturday who had originally been detained by police.

However, "simply arresting a few individuals cannot resolve the matter", Ng said.

Chan said one of the top priorities should be resettling victims and addressing their future needs, including housing.

He said he hoped his daughter would feel the love emanating from across Hong Kong.

"This kind of love symbolises the sincerity of Hong Kong people," said Chan, whose daughter winked as he spoke.

"I hope she can hold on to it."