As many as 40 people may have died in a massive fire at a warehouse party in California.

Nine people have already been confirmed dead but at least another 25 are missing, according to Oakland fire chief Teresa Deloach Reed.

Firefighters said there had been about 50 people inside the building when the tragedy happened in Oakland's Fruitvale district late on Friday night.

Alameda County Sheriff's Office spokesman Sgt Ray Kelly said the victims are believed to be people aged in their 20s.

Up to 40 feared dead in warehouse fire

He added that the coroner was preparing for a "mass casualty event" that could also include victims from other countries.


Crews saw no evidence that smoke detectors were activated at the electronic music event and there was no sprinkler system in the building, chief Deloach Reed was quoted as saying.

She said most of the people who died were found on the second floor.

She added: "This is a true loss for the city, for the firefighters who responded, and the people who lost family and friends. It's just tragic, a real tragedy."

Image: Oakland Fire Chief Teresa Deloach Reed said there is potential for the death toll to rise

Chief Deloach Reed said fire officials were still trying to determine how the blaze started but that the roof had collapsed, complicating efforts to recover bodies.

Referring to the number of known deaths, she said: "We are hoping that the number nine is what there is and that there are no more. But we have not done a complete search of the building.

"I pray that our fatality count does not go up but I believe there is potential for it to."

The blaze tore through the two-storey building at about 11.30pm during an event featuring electronic music act Golden Donna.

Police told local television station KTVU that the warehouse, known as the Oakland Ghost Ship, houses a group of artists and their studios.

Its website showed it to have a bohemian-type interior with a clutter of old sofas, pianos, turntables and statues.

Chief Deloach Reed said this clutter "made it difficult for people to escape".

Bob Mule, a photographer and artist who lives in the building and suffered minor burns, said: "It was too hot, too much smoke, I had to get out of there.

"I literally felt my skin peeling and my lungs being suffocated by smoke. I couldn't get the fire extinguisher to work."

Friends and family of party-goers have used social media to try and find out what has happened to their loved ones.

Some have been posting and getting information from the event's Facebook page.

Police have said anyone looking for those missing after the blaze should contact the Alameda County Sheriff's Coroner's Bureau.

Some 55 firefighters attended the scene, near the corner of 31st Avenue and International Boulevard.

Firefighters tackled the blaze inside but then had to go back outside when conditions changed, reports said.

Several hours later, the fire had not been officially declared under control, and there was still smoke coming from the an upper floor of the building.