The death toll from the massive fire that ripped through a Hong Kong housing estate this week has risen to 146, police said on Sunday, marking the world’s deadliest residential building blaze in more than four decades.

Officers from the Disaster Victim Identification Unit recovered more bodies after expanding their search to three additional high-rises in Wang Fuk Court, where seven of eight towers were engulfed by flames that burned for over 40 hours.

“As of 4:00 PM, the latest death toll stands at 146. We cannot rule out the possibility of further fatalities,” Chief Superintendent Tsang Shuk-yin said at a news conference.

Crowds of more than 1,000 people gathered at the Tai Po estate to pay respects, forming long queues as residents and visitors laid flowers and lit incense.

Authorities have launched an interdepartmental investigation to determine what triggered the blaze. Hong Kong’s anti-corruption watchdog has arrested 11 people, with three also facing police accusations of manslaughter.

The Indonesian consulate confirmed at least seven Indonesian nationals were among the dead, while the Philippine consulate said one Filipino overseas worker also died.

The Buildings Department has ordered a temporary halt to 30 private building projects across the city. Early findings indicate the fire spread quickly after starting on protective nets outside lower floors. Security chief Chris Tang said burning foam boards helped the flames race upward and into six additional buildings. Broken bamboo scaffolding also fell and carried the fire across the estate.

Preliminary tests showed the nets met fire safety standards, although the foam boards used around windows were highly flammable. Fire services chief Andy Yeung said alarm systems in all eight blocks “were malfunctioning,” forcing residents to alert one another door-to-door.

One firefighter died while battling the blaze, and dozens of injured residents remain hospitalised, including 11 in critical condition.

The government has announced a HK$300 million fund to support survivors. At least nine emergency shelters have been opened, and volunteers have set up stations offering food, clothing, medical care and psychological support.

The disaster underscored the risks faced by one of the world’s most densely populated cities, where steep hills, limited land and a longstanding construction boom have pushed millions into high-rise living. Tai Po, in the New Territories, has seen significant residential development in recent decades.

Authorities said all housing estates undergoing major renovation would be inspected in the aftermath of the tragedy.