Arsonsists are being blamed for torching three allotment sheds in Oswaldtwistle.
Two fire engines from Hyndburn were called to the allotments off Heron Way and when they arrived found the sheds on fire.
Around 10 firefighters used hose reels to put out the blaze and no injuries were reported.
The incident happened at around 1.45am on Thursday, August 6 and crews were at the scene for around 50 minutes.
Lancashire Fire and Rescue Service said they believe the fire was started deliberately and it is being investigated by the fire service and police.