Crews were sent from Ely and Barry to tackle the blaze, and were on the scene within minutes.

South Wales Fire and Rescue Service said: "An explosion occurred which injured three firefighters, one seriously. He subsequently died of his injuries."

The other two officers were released from hospital after treatment.

The area around the building - which was used as a community centre - has been sealed off so that the scene of the fire can be examined.

The identity of the firefighter who died has not been released, but is believed to have been based at Barry fire station. The coroner has been informed and an inquest will be held.

Residents from the area said half of the building had been completely destroyed by fire, and the other half was seriously damaged.

They said gangs of youths often gathered around the site, and there had been speculation as to whether the fire was started deliberately. An investigation by the fire service and the police forensic teams is currently being carried out.

Haydn Harries, who lives nearby said he was woken by the blaze.

"I could hear this crackling and banging as if someone was letting off fireworks in the street," he said.

"I came out to have a look and the old community hall, which is all wood, was on fire.

"It was a shock to hear there was a fireman caught in that explosion."

A full investigation into the fire is underway. Police and the South Wales Fire Service have sealed off the area around the fire. Neighbours say gangs of youths often gathered around the site and arson has yet to be ruled out.