ARSONISTS torched a former mill by starting at least five fires inside the building.

Firefighters spent three hours battling the blaze on Saturday night at the old Dorma factory in Casterton Avenue, Burnley.

They managed to tackle the fire in the empty mill, which has in the past been used for storage, and get it under control at around midnight.

The fire left the roof badly damaged and part of the inside gutted.

Firefighters have warned people not to go into the "dangerous" building.

However, they said that structurally it was safe.

Acting watch manager Dave Robinson said: "When we arrived there was smoke and fire coming out from the roof section of the mill on the ground floor. One section was fully alight when we got there and this was the main seat of the fire.

"There was quite a lot of smoke.

"We requested another two pumps and an aerial ladder.

"It turned out there were five separate seats of fire and we are treating them as deliberate.

"We managed to isolate the fire and stop it spreading to the other parts of the building.

"The structure of the building itself was not damaged.

"As far as I am aware, in the last 12 months, we have had rubbish fires outside the mill but not actually in the grounds of the mill."