ARSONISTS poured petrol onto the roof of a Bolton mill to start a fire last night.

Twenty firefighters tackled the blaze at Nortex Mill, Chorley Old Road.

The fire was relatively small, but it triggered the unit's sprinkler system and caused substantial damage.

It is understood the firm operating there, which distributes till rolls, had only been trading for three weeks.

Firefighters were called when a passer-by smelled smoke coming from the mill.

Leading firefighter Karsten Boyle said: "When we arrived there was a strong smell of petrol which led us to the fire.

"Because it was above us it was a difficult one to tackle.

"There was fairly substantial water damage from the sprinklers but they probably contained it."

The unit was an annex to the main building with its own pitched roof and no other units were damaged.

Firefighters were mopping up after two blazes in Bury this morning.

The former Tudor Glass factory unit in Manor Street was destroyed by fire, while arsonists are being blamed for an attack on a disused warehouse in Crostons Road.

Local fire crews were forced to call in neighbouring stations to help deal with both incidents.

The fire at the Manor Street building was spotted just after 1.30am. Tudor Glass moved out of the property some time ago and the building is being used for storage.

A fire brigade spokesman said: "The caused of the blaze is as yet unknown although the building has been severely damaged. The roof has gone and a building inspector is due to look at the site to see if it needs to be demolished."

As firefighters fought the Manor Street blaze, arsonists struck for the second time in three weeks at Crostons Road, targeting a disused warehouse which sustained heavy damage in the first attack.

Four fire crews were involved in the second blaze.

Bury CID were informed and detectives visited the scene this morning.