Hong Kong’s leader said on Tuesday a judge-led committee will investigate the cause of the city's deadliest fire in decades and review oversight of building renovations blamed for fanning an inferno that killed at least 156 people.

Police have arrested 15 people on suspicion of manslaughter in a criminal inquiry into last week's tragedy at the Wang Fuk Court complex, and 12 have also been arrested in a corruption probe. It is unclear if any of those people were arrested on both counts.

Authorities have pointed to substandard plastic mesh and insulation foam used during renovation works at the high-rise estate for fuelling a blaze that quickly spread to seven of its eight towers, home to more than 4,000 people.

"In order to avoid similar tragedies again, I will set up a judge-led independent committee to examine the reason behind the cause and rapid spreading (of the fire) and related issues," John Lee, Hong Kong's chief executive, told a press conference.

Investigators have completed sweeps of all but two of the burnt-out towers, finding residents' bodies in stairwells and on rooftops, trapped as they tried to flee the smoke and flames. Around 30 people are still missing.

Some groups in the Chinese-ruled city have called for more transparency and accountability, amid warnings from authorities that any attempts to politicise the disaster would be severely punished.

A student from one of the groups was detained and later released on bail, and local media reported two others were being investigated for possible sedition. Police have not commented on the cases.

"I will not tolerate any crimes, particularly crimes that exploit the tragedy that we are facing now," Lee said, when asked about the cases. He did not comment on the specifics.

International rights groups have said the incidents demonstrate government attempts to suppress criticism.

"It's crucially important not to treat those demanding answers for the tragic fire as criminals," said Elaine Pearson, Asia director at Human Rights Watch.

China's national security office has warned individuals against using the disaster to "plunge Hong Kong back into the chaos" of 2019, when massive pro-democracy protests challenged Beijing and triggered a political crisis.

Legislative elections due to take place on Sunday will go ahead as planned, Lee said.

Turnout for that vote - in which only candidates screened by the government as "patriots" can run - could serve as a barometer of public frustration over the handling of the fire.

RESIDENTS WARNED OF FIRE RISKS

Residents of Wang Fuk Court were told by authorities last year they faced "relatively low fire risks" after complaining about fire hazards posed by the renovations, the city's Labour Department said.

The residents raised concerns in September 2024, including about the potential flammability of the mesh that contractors used to cover the bamboo scaffolding, a department spokesperson said.

Tests on several samples of mesh on the buildings at the time of the blaze did not match fire-retardant standards, officials overseeing the investigations told a press conference on Monday.

Contractors working on the renovations used the substandard materials in hard-to-reach areas, effectively hiding them from inspectors, the officials added.

Authorities have also said foam insulation used by contractors to cover windows also fuelled the flames and that fire alarms at the complex were not working properly.

Thousands of the city's residents have paid tribute to the victims, who include nine domestic helpers from Indonesia and one from the Philippines.

Vigils are also due to take place this week in Tokyo, Taipei and London.

A funeral parlour in central Hong Kong held a memorial on Tuesday to mark the seventh day since the deadly fire, a Chinese custom known as soul return day.

Hundreds prayed, wept, and made lotus-shaped paper offerings, a symbol of spiritual rebirth in mourning rituals.

"I hope that...people can release what’s in their hearts. That way, it will be easier for all of us to move forward in life," said Bryan Kam, general manager of the Kowloon funeral parlour.

SEARCH MOVES TO WORST-AFFECTED BUILDINGS

The remaining buildings being scoured for remains and evidence are the worst damaged. The search may take weeks, authorities said.

Images shared by police showed officers clad in hazmat suits, face masks and helmets, inspecting rooms with blackened walls and furniture reduced to ashes, and wading through water used to douse fires that raged for days.

Residents who escaped the blaze must now try to get their lives back on track.

Nearly 1,500 people have been moved out of evacuation centres into temporary housing, with a further 945 put up in youth hostels and hotels, authorities said.

More than 60 pets, including 34 cats, 12 dogs and seven turtles, perished in the fire, the Society for the Prevention of Cruelty to Animals said. More than 200 were rescued.