Hong Kong’s deadliest fire in decades burned through the night, leaving at least 44 people dead and 279 reported missing with rescuers still pulling residents from blazing high-rise apartment buildings into the morning.

Police had arrested three men on suspicion of manslaughter in connection with fire which began Wednesday afternoon in a housing complex in Tai Po district, a suburb in the New Territories. By Thursday morning local time, the fire was yet to be put out and rescues continued.

Hundreds of residents were evacuated as the fire spread across seven of the eight towers in the Wang Fuk Court complex, as bright flames and smoke shot out of windows.

Forty of the 44 fatalities were declared dead at the scene, officials said. At least 62 others were injured, many suffering from burn and inhalation injuries.

Authorities suspected some materials on the exterior walls of the high-rise buildings did not meet fire resistance standards, as the rapid spread of the fire was unusual.

Police also said they found Styrofoam materials -- that are highly flammable -- outside the windows on each floor near the lift lobby of the one unaffected tower, believed to be installed by a construction company.

“We have reason to believe that those in charge of the construction company were grossly negligent,” said Eileen Chung, a senior superintendent of police. The three men arrested, aged 52 to 68, are the directors and an engineering consultant of the firm.

The fire at four of the buildings was “coming under control” by Thursday morning, according to the Fire Services Department.

Officials said the fire started on the external scaffolding of one of the buildings, a 32-story tower, and later spread to inside the building and then to nearby buildings, likely aided by windy conditions.

Chinese leader Xi Jinping on Wednesday expressed condolences to the firefighter who died and extended sympathies to the families of the victims, according to state broadcaster CCTV. He also urged efforts to minimize casualties and losses.

John Lee, the city’s chief executive, said the government will prioritize the disaster and halt public efforts for the Dec. 7 elections for the Legislative Council, the city’s legislature. He didn’t say if the elections could be delayed but said decisions would come “a few days later.”

The housing complex consisted of eight buildings with almost 2,000 apartments housing about 4,800 residents, including many elderly people. It was built in the 1980s and had recently been undergoing a major renovation.

Fire chiefs said high temperatures at the scene made it difficult for crews to mount rescue operations. A column of flames and thick smoke rose as the blaze spread quickly on bamboo scaffolding and construction netting that had been set up around the exterior of the buildings. About 900 people were evacuated to temporary shelters.

Authorities said that hundreds of firefighters, police officers and paramedics were deployed. Firefighters aimed water at the intense flames from high up on ladder trucks.

The blaze, which started mid-afternoon, was upgraded to a level 5 alarm -- the highest level of severity -- as night fell. Authorities said that conditions remained very challenging for firefighters.

“Debris and scaffolding of the affected buildings (is) falling down,” said Derek Armstrong Chan, deputy director of Fire Service operations. “The temperature inside the buildings concerned is very high. It’s difficult for us to enter the building and go upstairs to conduct firefighting and rescue operations.” The fire department said it received “numerous” calls requesting assistance.

Firefighters deployed more than 200 fire vehicles and about 100 ambulances to the scene.

A 37-year-old firefighter was among the dead, while another firefighter received treatment for heat exhaustion, said Director of Fire Services Andy Yeung.

District officials in Tai Po have opened temporary shelters for people left homeless by the fire.

“I’ve given up thinking about my property,” a resident who only provided her surname, Wu, told local TV station TVB. “Watching it burn like that was really frustrating.”

Tai Po is a suburban area in the New Territories, in the northern part of Hong Kong and near the border with the mainland Chinese city of Shenzhen.

Bamboo scaffolding is a common sight in Hong Kong at building construction and renovation projects, though the government said earlier this year that it would start phasing it out for public projects because of safety concerns.

The fire is the deadliest in Hong Kong in decades. In November 1996, 41 people died in a commercial building in Kowloon in a level 5 fire that lasted for around 20 hours.