HONG KONG — A massive high-rise fire in northern Hong Kong has killed at least 44 people, officials said Thursday, as the blaze continued to smolder and police arrested three men on suspicion of manslaughter.

Hundreds of residents remained unaccounted for in what authorities called the city’s deadliest blaze in decades.

The fire broke out Wednesday afternoon across an eight-building residential complex in Tai Po known as Wang Fuk Court, which contains roughly 2,000 apartment units and is among the densely populated financial hub’s many towering blocks. Large flames initially engulfed bamboo scaffolding surrounding buildings undergoing maintenance, fire officials said.

Crews raised the death toll early Thursday from 36 to 44 as smoke continued to pour from several floors. Police said three men had been arrested but released no details about the alleged offenses.

Witnesses described chaotic scenes as flames spread between buildings. An AFP reporter at the site heard loud cracking sounds—believed to be burning bamboo poles—and saw ash and embers raining down as plumes of smoke rose into the night sky.

More than 900 people sought refuge in temporary shelters, according to Chief Executive John Lee, who said he was “deeply saddened” and that government departments were assisting displaced residents.

Authorities said they are investigating both the cause of the fire and whether exterior building materials contributed to its rapid spread. Officials said charred scaffolding collapsed from several blocks, while flames burst through apartment windows.

“The temperature at the scene is very high and there are some floors where we have been unable to reach people who requested help, but we will keep trying,” said Derek Armstrong Chan, deputy director of fire service operations. He said wind and drifting debris likely helped carry the fire from one building to another.

Chinese President Xi Jinping expressed condolences to victims and the family of the firefighter killed, state media reported. Xi called for authorities to “make every effort to extinguish the fire and minimise casualties and losses,” according to CCTV.

Evacuations continued through early Thursday, with buses ferrying residents away from the danger zone. Adjacent buildings were also cleared, and parts of a nearby highway were closed.