Firefighters were called to land off the A61 Wakefield Road between Rothwell and Robin Hood at 1.30pm on September 15 after three of the disused buildings were caught up in a large blaze.
A plume of thick black smoke from the burning buildings was visible from Leeds city centre.
Crews from Hunslet and Rothwell fire stations used three large jets to douse the flames.
West Yorkshire Police officers were called to manage traffic as two fire engines blocked one lane of the road.
The incident took around 90 minutes to be brought under control.
While the cause was still under investigation, a fire service spokesperson said: “We believe it is most likely the fire was started deliberately.”