An investigation was today under way into the cause of a blaze which destroyed a historic mill.

Residents from more than 100 homes and workers at a nearby petrol station were evacuated yesterday afternoon as the inferno raged at an aerosol factory at Clough Mills, Halifax Road, Shelf.

Firefighters were called at 2.45pm to Decosol Ltd, a family-run firm which manufactures chemical products for cleaning cars. It is believed no-one was in the building at the time.

Eighteen appliances and 112 firefighters attended from across the Bradford district. No-one was injured.

Businesses and roads surrounding the mill were closed as concerns were raised about explosions within the building.

Crowds watched as the five-storey mill collapsed. Keith Robinson, manager at Bradford fire station, said: "We evacuated because of the risk of explosion and the danger from the collapsing building.

"Aerosols were popping and there were six tanks containing 60,000 litres of ethanol near the building."

He said the fire spread quickly because of the mill's timber floors. "The design of building and the fact that it is very old makes it more complicated and more difficult to bring the blaze under control."

Evacuated residents were moved to Shelf Community Hall.

David Ackroyd, who lives in Halifax Road, was one of the first people at the scene.

"I saw flames leaping into air and the fire had obviously taken hold very quickly," he said.

Paul McMillan, a sales executive, was evacuated by police from his home in Shelf Hall Lane. "I was with my neighbour who has a young baby when the police stopped the car and said we could not go home. The baby had to be taken and cared for elsewhere."

Major disruption was caused to rush hour traffic when Halifax Road and Denholme Gate Road were closed for several hours.

The cause of the fire is not known and an investigation has started by West Yorkshire Police and the West Yorkshire Fire Service. A police spokesman said: "It's not being treated as suspicious at this stage but a joint investigation will continue today to establish the cause."

This morning two crews were still at the scene, damping down. A fire service spokesman said: "We are likely to be there for the forseeable future."