HK fire toll rises to 128, rescuers make final search

The death toll from Hong Kong's worst fire in nearly 80 years has risen to 128 and about 200 people remain missing from the high-rise residential complex that was engulfed by the blaze, the city's security chief says.

Security Chief Chris Tang told reporters at the scene that the search for victims was continuing and the numbers could still rise.

The fire hit the Wang Fuk Court development in the northern district of Tai Po on Wednesday afternoon and was only fully extinguished on Friday morning.

Dozens of people including firefighters were injured in the blaze.

Crews were prioritising apartments from which they received more than two dozen calls for assistance but were unable to reach, Derek Armstrong Chan, a deputy director of Hong Kong Fire Services told reporters.

It took more than 1000 firefighters some 24 hours to bring the blaze under control, and even nearly two days later, smoke continued to drift out of the charred skeletons of the buildings from the occasional flare-up.

The final search of the buildings is expected to be completed later on Friday AEDT at which point officials have said they will officially end the rescue phase of their operation.

Firefighters were working hard to prevent the debris and embers from flaring up.

It was unclear how many people could possibly be inside the buildings, which had almost 2000 apartments and some 4800 residents.

"We will endeavour to force entry into all the units of the seven blocks concerned so as to ensure that there are no other possible casualties," Chan said.

He said the blaze spread "exceptionally fast" across the towers, and emergency workers struggled to gain access inside.

"Debris and scaffolding were falling from upper floors," Chan told reporters.

"There are also other reasons like high temperature, darkness ... (and) emergency vehicle access was blocked by fallen scaffolding and debris, making our access to the building very difficult."

Police arrested two directors and an engineering consultant of Prestige Construction, a firm contracted to perform maintenance on the buildings.

Police said those arrested were under suspicion of manslaughter for using unsafe materials.

"We have reason to believe that the company's responsible parties were grossly negligent, which led to this accident and caused the fire to spread uncontrollably, resulting in major casualties," police superintendent Eileen Chung said.

Prestige did not answer repeated calls for comment.

Police seized bidding documents, a list of employees, 14 computers and three mobile phones in a raid of the company's office, the government added.

It was Hong Kong's deadliest fire since 1948, when 176 people were killed in a warehouse blaze.

In a telegram to Hong Kong's bishop, Cardinal Stephen Chow Sau-Yan, Pope Leo sent "spiritual solidarity to all those suffering from the effects of this calamity, especially the injured and the families who grieve".

Hong Kong leader John Lee said the government would set up a $HK300 million ($A60 million) fund to help residents.

Chinese companies and groups, including car makers Xiaomi, Xpeng and Geely as well as the charity foundation of Alibaba's founder Jack Ma and Tencent announced donations.

The eight blocks of apartments were under renovation and clad in bamboo scaffolding and green mesh.

Police also said they found foam material sealing some windows on one unaffected building, installed in year-long maintenance work.

The city's development bureau has discussed gradually replacing bamboo scaffolding with metal scaffolding as a safety measure.

With AP