FIRE chiefs today blamed building materials used in a tanning studio for the extent of the blaze which gutted the property.

An investigations is under way at the Sunworld Tanning Centre, Blackburn Road, Darwen, and police said arson had not been ruled out.

Fire crews from Darwen, Oswaldtwistle and Blackburn were called to the blaze in the early hours of Sunday after residents reported hearing an explosion and saw smoke pouring out of a window.

Jim Owen, assistant divisional officer for Lancashire Fire and Rescue said they were lucky that nobody was in the building when the blaze started because it spread so quickly.

He said the explosion could have been caused by a backdraught and said: "Unfortunately, many of the rooms walls on the ground floor were clad in uPVC and the sun bed cubicles constructed from MDF boarding. Both are materials that would greatly have assisted the evolution of fire gases and the power of the backdraught and add to the risk to people trying to escape from buildings at the time of the fire.

"That is the reason why we do not recommend thos1e materials as internal wall finishes. The building was empty at the time of this fire and thankfully no one was walking across the front of the shop when the plate glass window blew out with the explosion.

"However, had we been called two or three minutes earlier it might have well struck fire fighters on the scene."

"There's no doubt that the high combustibility of many of the building materials, coupled with the time the fire had to develop led to a fire-spread we had great difficulty stopping."

The owners of the shop were not available for comment today.

Detective Sergeant Ian Critchley from Darwen CID said they had not ruled out the possibility it was an arson attack and were still testing debris brought out of the gutted building. He urged anyone who saw anyone hanging around the shop to come forward.

People can telephone Darwen CID on 01254 353842.