DOZENS of firefighters spent four hours tackling a blaze at a derelict Bacup mill last night.

Crews from Bacup, Rawtenstall, Todmorden, Rochdale, Accrington, Nelson and Burnley were called to Tong Bridge Mill, Springfield Avenue, at 7.20pm.

Four nearby houses were temporarily evacuated and it took crews two hours to surround the blaze before firefighters were able to get inside the building.

One crew was still at the scene of the fire this morning.

It is not yet known how the fire started or if it was deliberate but firefighters believe the single storey section of the building was filled with bales of cotton.

Speaking at the scene, Assistant Divisional Officer at Burnley Fire Station Steve Kennedy, who was in charge of the operation, said: "The whole of the single storey section was well alight when we arrived and we've subsequently had to break in at both sides.

"We managed to stop it spreading into the three storey section."

Fire crews used five jets and an aerial ladder as they tackled the blaze from outside before it was deemed safe enough for officers to enter the building using breathing apparatus.

By 9.20pm the fire was under control but crews were still not entirely sure if it was out or if there were still hidden pockets of fire.

Mr Kennedy said the scale of the operation meant the fire service would be stretched if another incident had occurred elsewhere in the area.

He said: "It was a big operation. We got the fire surrounded. We were there for the majority of the evening.

"It was a major fire. It's not only taken a tremendous effort from the firefighters involved but is also tying up resources should we get another incident elsewhere."

Crews began leaving the scene shortly after 11pm.