On Friday, the city's anti-corruption watchdog arrested eight people in connection with the blaze. Authorities outlined how malfunctioning fire alarms and flammable construction materials led to the worst residential building fire in the world since 1980.

In the early hours of Saturday, AFP saw citizens placing flowers near Wang Fuk Court -- an eight-building complex that was the site of the devastating fire -- to grieve for the victims.

"May your spirits in heaven always keep the joy alive," read a note of remembrance placed at the site.

On Friday, families scoured hospitals and victim identification stations hoping to find their loved ones, with around 200 people still listed as missing and 89 bodies as yet unidentified.

Flames moved quickly at the housing estate in Tai Po district on Wednesday afternoon, spreading through seven of the eight high-rises and transforming the densely packed complex into an inferno.

Authorities said preliminary investigations suggested the fire had started on protective netting on the lower floors of one of the towers and that "highly flammable" foam boards, as well as bamboo scaffolding, had contributed to its spread.

Fire services chief Andy Yeung said they had discovered that alarm systems in all eight blocks "were malfunctioning", and that they would take action against the contractors.

"We have been visiting the scene every day," said a man surnamed Fung who was looking for his 80-year-old mother-in-law.

"She is on antibiotics... so she is always sleeping. There was no fire alarm so she might not have known there was a fire," he said.

The city's anti-corruption watchdog said the eight people it had arrested on Friday included "consultants, scaffolding subcontractors and (a) middleman of the project".

On Thursday, the body had launched a probe into the renovation project, hours after police said they had arrested three men on suspicion of negligently leaving foam packaging at the fire site.

- 'Burning red' -

The blaze was "largely extinguished" by Friday morning after burning for more than 40 hours, the fire services said, announcing they had finished their search of more than 1,800 flats for survivors.

Workers brought out bodies in black bags, with an AFP reporter counting four in one 15-minute period.

"We do not rule out the possibility that police will find more charred remains when entering (the building) for detailed investigation and evidence collection," Hong Kong's security chief Chris Tang told a press conference.

Vehicles unloaded corpses at a mortuary in nearby Sha Tin, another reporter saw, with families arriving in the afternoon for identification.

At one hospital there, a woman surnamed Wong was looking for her sister-in-law and her sister-in-law's twin, with no luck.

"We still cannot find them. So we are going to different hospitals to ask if they have good news," the 38-year-old told AFP in tears.

The government said police have activated a specialist disaster victim identification system to help with locating the missing.

On Friday, dozens were still in hospital, with 11 in critical condition, and 21 listed as "serious".

"One building went up in flames and it spread to two more blocks in less than 15 minutes," a 77-year-old eyewitness surnamed Mui told AFP.

"It was burning red, I shudder to think about it."

- Investigations begin -

The blaze was Hong Kong's deadliest since 1948, when an explosion followed by a fire killed at least 135 people.

Lethal fires were once a regular scourge in densely populated Hong Kong, especially in poorer neighbourhoods, but improved safety measures have made them far less common.

Security chief Tang said the full investigation into the fire's causes could take up to four weeks.

Authorities had found temporary accommodation for around 800 people, the government said Friday.

Nine emergency shelters were also in operation, accommodating around 720 people overnight.

A spontaneous community effort to help firefighters and those displaced had become a well-oiled machine by Friday.

Separate supply stations for clothes, food and household goods were set up at a public square near the towers, as well as booths providing medical and psychological care.

So much was donated that organisers put out a call on social media saying no more was needed.