Shock is giving way to anger in Hong Kong after a massive fire ripped through a densely populated subsidised housing estate on Wednesday, killing at least 128 people and critically injuring dozens.

Authorities say substandard mesh and plastic sheets on the buildings' windows may have spread the blaze, which raged for more than a day.

Firefighting operations have now ended, with dozens of residents still unaccounted for.

Questions are mounting as to how the fire at Wang Fuk Court spread so rapidly and who is responsible, with many calling it a man-made disaster.

Three people in charge of renovating the blocks are under arrest for manslaughter, and authorities have launched a corruption inquiry.

A post that has gone viral on social media in the wake of the blaze reads: It's not an accident.\

Several residents have revealed in interviews that the fire alarm did not sound when the fire broke out. Authorities said on Friday that they had checked the fire alarms in all eight blocks and found that they were not working properly.

Kiko Ma, who owns an apartment at Wang Fuk Court, says the alarms had been turned off amid renovation works, as construction workers regularly used fire escapes to get in and out of the building.

This was preventable... A lot of people did not do their duties, the 33-year-old tells the BBC, claiming that the renovation firm used poor quality, flammable materials. Residents often saw construction workers smoking and found cigarette butts along their window ledges.

This is Hong Kong's deadliest fire in at least 63 years - already having surpassed the toll of the August 1962 inferno in the Sham Shui Po neighbourhood, which killed 44 people.

Built in the 1980s, Wang Fuk Court in Hong Kong's north-eastern Tai Po district comprises eight 31-storey buildings, seven of which went up in flames. The apartments here are sold at subsidised prices, but day-to-day affairs in the estate are managed by privately appointed firms.

According to the 2021 census, the complex was home to about 4,600 people - nearly 40% of whom were 65 or older.

Police are investigating whether mesh netting, plastic and canvas sheets used during renovations met fire safety standards. In a presser on Friday they attributed the rapid spread of the fire to styrofoam blocks placed outside the windows of the apartments, apparently to protect them from the debris and dust.

Residents at Wang Fuk Court had expressed unease about renovation plans when they were announced last year. Reports of those concerns have now resurfaced online, sparking accusations around a lack of transparency.