Crates of cardboard stored for recycling were set alight at a supermarket.
Cleckheaton firefighters were called to loading bays at Tesco in Northgate at 10pm last night.
Watch Commander Dan Gledhill said they were there for about 45 minutes after the “large amount” of cardboard, stored in crates, was set alight.
It is thought the fire was started deliberately.
No people were injured or at risk, but the metal crates were damaged.