Four fire crews were called out to extinguish a blaze in a former Indian takeaway in Chorley.
Officers say the boarded up premises in Brooke Street had been broken into and rubbish set alight.
Engines from Chorley, Leyland and Bamber Bridge attended the blaze at the former Moonlight takeaway at around 3.50pm yesterday.
A fire brigade spokesman said: "The property used to be an Indian takeaway, but it hasn't been occupied for a while.
"We had a fire there approximately two or three years ago and it went through the roof. Since then it hasn't been used.
"It is boarded up, but someone has gained access and set alight a big pile of rubbish."
Firefighters with breathing apparatus tackled the blaze with hose reels. They also used a thermal imaging camera to check the building.