POLICE were today hunting a suspected arsonist after an explosion ripped through a mill complex and blew off part of the roof.

Fire crews from Darwen, Blackburn and Accrington fought the blaze in an admininstration block at Gillibrands Mill, Hollins Grove Street, Darwen, through last night after the blast, at 9.20pm.

It is believed police were today waiting to speak to a man who attended hospital in Blackburn with burns to the hands yesterday evening, in connection with the incident.

And one neighbour said he had heard a car speeding away from the scene.

The two-storey admin block involved in the blaze is next to several industrial units.

It provided offices for several companies, including a distribution firm and an alarm business, but was gutted by the fire.

The mill was well alight when fire crews were called. The roof was blown off and initial reports said one of the doors had also been blown out by the explosion.

Police closed the road and several other roads in the area during the night, but had re-opened all but Hollins Grove Street by this morning.

The road was expected to be closed for most of today, as debris blown across the road was cleaned up and investigators sifted through the wreckage to find the cause of the blaze, although the fire is being treated as suspicious.

Mill owner Michael Ingham, who has owned the property for about 30 years with partner Alan Thompson, and who had an office and his own records destroyed in the fire, said: "I got a call last night at about 9.30pm saying the block was on fire and I came straight down.

"It is a complete mystery to me why anyone would want to do this. I have owned the whole building for about 30 years and now we will have to start all over again from scratch.

"I just want to know who has done this to my business."

A nearby resident Paul Monk, 31, said: "I heard a loud explosion at about 9.15pm last night. At first I thought it was my car. When I saw the flames reflected in the window I ran out to the front and saw the mill was on fire. So I called the fire brigade straight away."

Another neighbour, who asked not to be named, said: "I saw the flames coming from the mill late last night and I also heard a car speeding off down the road. I later heard someone was taken to hospital with burns."

Assistant divisional officer with Darwen fire brigade Dave Allan said: "The blaze is being treated as suspicious and the cause of the fire is now under investigation."

Sergeant Stewart Bruce, from Blackburn police, said: "Investigations are continuing today into why it exploded, which is not immediately clear at the moment.

"It appears something in the unit may have exploded, but we are not sure what. The road was closed for the investigation, but also due to the debris aspect of it. It will be opened again when everything has been tidied away and we think it is completely safe."

Council inspectors are likely to be on the scene today to decide whether the building should be declared unsafe.