Hong Kong police on Thursday arrested the executives of a construction company on manslaughter charges over the city's worst fire in almost 80 years, which killed at least 83 people with about 300 still listed as missing.

Firefighters had mostly doused the blaze that tore through the Wang Fuk Court housing complex in the northern district of Tai Po, which had been undergoing renovations and was wrapped in bamboo scaffolding and green mesh.

Rescuers battled intense heat and thick smoke for more than a day as they fought to reach residents feared trapped on the upper floors. Video showed firefighters with flashlights searching through the charred remains of the towers on Thursday night.

A distraught woman carrying her daughter's graduation photograph searched for her child outside a shelter, one of eight that authorities said are housing 900 residents.

"She and her father are still not out yet," said the 52-year-old, who gave only her surname, Ng, as she sobbed. "They didn't have water to save our building."