Hong Kong leader John Lee on Tuesday announced an independent inquiry into the housing block fire tragedy that claimed at least 151 lives.

Lee said there had been serious problems regarding construction and supervision, and that people would be held accountable.

What do we know about the Hong Kong fire probe?

Lee, the territory's chief executive, said a judge-led committee would conduct a review of building practices.

Officials have said the blaze spread rapidly through exterior scaffolding netting that failed to meet fire-resistance standards.

Lee said authorities had already identified multiple failures and that reforms would be needed in safety rules, supervision procedures and overall standards.

"I call for a thorough investigation and serious reform," said Lee. "We will overcome the obstacles of vested interests and pursue accountability, regardless of who he or she is."

"The shortcomings will be addressed," he said. "The bottlenecks will be addressed. And we will reform the whole building renovation system to ensure that such things will not happen again."

While Hong Kong normally relies on such "commissions of inquiry" for major fact-finding investigations, a system inherited from British rule, Lee used the term "independent committee."

What caused the Hong Kong blaze?

Authorities have highlighted the role of high winds and substandard materials, including highly flammable foam panels used to block windows and green construction netting that was legally required to be flame-retardant.

The blaze spread to seven of the Wang Fuk Court residential complex's eight towers. The fire burned for more than 40 hours.

Lee said those responsible had mixed unsafe netting with compliant material "so as to cheat the inspection."

Police and Hong Kong's anti-corruption agency have detained 14 people — including construction company directors and an engineering consultant. Fifteen people have also been arrested on suspicion of manslaughter. It is unclear which individuals overlap between the two investigations.

While some civic groups have called for greater transparency, officials have warned that attempts to politicize the tragedy will be met with severe consequences.

Local media reported that two individuals are under investigation for suspected sedition, while a student was detained and later released on bail. Police have not commented on the cases. Lee said: "I will not tolerate any crimes, particularly crimes that exploit the tragedy that we are facing now."

International human rights groups have expressed concern. "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.

Edited by: Elizabeth Schumacher