A blaze which ripped through a Bradford mill complex is not being treated as arson.

But the cause of the fire at the Cannon Mills shopping complex in Great Horton Road on Thursday night remains a mystery.

More than 60 firefighters spent more than an hour bringing the blaze under control at the four-storey building which is undergoing a £15million revamp to create a shopping village.

After the outbreak, fire investigators and police scenes-of-crime officers sifted through the charred remains to try to find the cause.

But Detective Inspector Shaun Berry, of Bradford North CID, said police were no longer investigating the fire.

He said: "The police and fire investigation has been done and we are not investigating it as a crime at the moment. We do not know how the fire started. It is a mystery.

"It could have been accidental as easily as it could have been deliberate.

"There is no trace of any accelerant or of forced entry and from our house-to-house inquiries nobody has seen anything suspicious. Nor is there any sign of an electrical fault or of smouldering cigarettes.

"In the absence of a new line of inquiry, we are not now investigating it."

The mill is currently used as a market hall on Sundays.

Keighley businessman Sharif Tariq, who owns the complex, said damage was only superficial and the market went ahead as normal yesterday.

Mr Tariq said: "There were only two stalls affected by the fire. We have held the market as normal today, though we had to close one corner of it.

"It could have been a lot worse. It was mostly smoke damage - there is no structural damage."

Mr Tariq bought the complex in 1998.

In February last year the market hall was mostly destroyed after it was set alight by arsonists.

The multi-million-pound redevelopment plans include providing a one-stop wedding centre, health suites, shopping and housing.