OAKLAND (United States) • Anguished family members yesterday awaited news of the fate of over a dozen people still unaccounted for after a fire gutted a makeshift nightclub in Oakland, California, in one of the deadliest structure fires in the US in the past decade.

Partygoers at the two-storey converted warehouse were asphyxiated last Friday night by thick black fumes, which poured from the building's windows for several hours.

Twenty-four people are confirmed dead, but officials said they fear the death toll could reach 40.

Some of the missing are from overseas, making identification of the victims - thought to be in their 20s and 30s - more difficult.

Oakland officials described the warehouse, known as the Ghost Ship in the Fruitvale neighbourhood, as "a labyrinth of artist studios".

They said escape from the building, which had only two exits, might have been complicated because the first and second floors were linked by a makeshift staircase made of wooden pallets.

Firefighters said the building seemed to have no sprinklers or smoke detectors.

"We know that there are bodies in there that we cannot get to, that have been seen but have not been recovered," said Sergeant Ray Kelly of the Alameda County Sheriff's Office.

The structure had a permit to function as a warehouse, but not as a residence or a party site.

Officials said they were investigating reports that the building had also been used as a living space.

At a news conference, Oakland Mayor Libby Schaaf said: "This is complicated. It's going to take us time to do the investigation that these families deserve."

One survivor, musician Aja Archuleta, 29, was scheduled to perform at the electronic music party at about 1am and was working at the door when the fire broke out at about 11pm last Friday.

"There were two people on the first level who had spotted a small fire that was growing quickly," she said. "It was a very quick and chaotic build, from a little bit of chaos to a lot of chaos."

Family members of those missing expressed anguish over spending hours waiting to learn if their relatives were inside.

Mr Daniel Vega, 36, said he was "infuriated" waiting to hear news about his 22-year-old brother Alex.

"Give me some gloves. I've got work shoes. I'm ready," Mr Vega said. "Let me find my brother. That's all I want."

Even without a full accounting, the fire was one of the deadliest in the United States in many years.

In 2003, 100 people were killed in a fire in a nightclub in Warwick, Rhode Island.

NYTIMES, AGENCE FRANCE-PRESSE