POLICE were today hunting arsonists who put firefighters' lives in danger after they torched a former wall coverings factory in Nelson.

Around 40 firefighters took 24 hours to put out the blaze at John Wilman's mill, in Reedyford Road, after the fire broke out at 10pm on Saturday.

Fire crews today told how they had to cut parts of the second-storey floor away to aim jets at the flames on the floor below. Officers were still at the scene last night dampening down what remained of the three-storey building.

Police and fire bosses are now investigating the cause of the blaze that ripped through the 300m-long building. And they revealed they were in talks with the site owners in a bid to make it more secure and prevent a repeat of the inferno - the second major fire there in 12 months.

By the time the fire took hold, firefighters had already been called to the site twice on Saturday to deal with minor rubbish fires believed to be started by youngsters.

Firefighters from Burnley, Nelson, Colne, Hyndburn and Blackburn were faced with dangerous conditions during the incident.

A handful of witnesses watched as tonnes of water from the aerial platform were used to extinguish flames from above which reached 10ft beyond the building's roof.

Sub Officer Mark Woodward from Nelson said: "The firefighters did superbly to limit the spread to 25 metres and put in a good stop.

"But it was very dangerous as the fire was burning in several different places and, most worryingly, spread between the double flooring at each level.

"There were 16 breathing apparatus, four jets and the aerial platform.

"It was well alight when we arrived and is thought to have been started deliberately inside."

One witness, who declined to be named, of Reedyford Road, said: "Something needs to be done to secure the site.

"There was smoke everywhere and it is a real pain on a Saturday night."

PS Simon Peyton of Pennine Police said an investigation would be launched after the fire service had completed their fire report.

He said: "This building is an ongoing problem as the site is insecure. We are liaising with the owners to firm up the security measures."

John Wilman is a former wallcoverings factory. which has been empty for several years.

"The building has been targeted several times before.

In July last year families in nearby houses had to be evacuated after a serious blaze, which was also treated as suspicious at the time.

Neil Watson, planning manager for Pendle Council, said: "We know the building as Riverside mill.

"The Bhatti brothers used to own it but we now understand it is owned by Lynwood."