A park bench was set on fire by arsonist causing large amounts of black smoke.
Three fire crews were call to put out the plastic bench on playing fields off Alan Ramsbottom Way, Great Harwood.
Shaun Carlisle, acting crew manager at Hyndburn, said they are treating the fire as deliberate.
He said: “The bench was completely destroyed. It was a plastic bench and completely disintegrated setting off lots of smoke.
“We had quite a few calls about it as people thought it was something much worse than it was with all the smoke and it was near an industrial estate.
“We had three fire appliances attend which wasn't ideal.”
The incident happened at around 9pm on Sunday, July 7.