Five people have been arrested over a fire at a historic mill used as a filming location for Peaky Blinders and Downton Abbey.
West Yorkshire Police say they are treating the blaze at Dalton Mills in Keighley as arson.
A huge fire engulfed the Grade II listed building on Thursday, with footage showing flames and black smoke billowing into the air.
Police say no-one was in the building at the time.
A spokesperson for the force said: “Five arrests have been made and the investigation is ongoing.
“Bradford CID would like to appeal for any witnesses who may have seen anything suspicious around 11.30am – 12pm.
“They are also looking for drivers who were in the area at the time who might have dash cam to come forward.”
At the height of the blaze, which started at around noon, 120 firefighters were at the scene. Two fire crews remained at the site for damping down on Friday morning, to prevent the fire from re-igniting.
On Thursday, Bradford Council said it had opened the town’s leisure centre to provide shelter for residents affected by the blaze, which affected 100% of the historic building.
The fire service told people living nearby to keep windows and doors closed, and to avoid travelling through the area because of the smoke.
The Victorian building was once said to be the largest textile mill in Yorkshire, employing around 2,000 workers.
It has been used as a filming location in hit BBC series Peaky Blinders, as well as The Great Train Robbery, Downton Abbey and 2016 film The Limehouse Golem, starring Bill Nighy.