Teenagers are being blamed for setting fire to a seating area in Memorial Park.
Firefighters were called to the park in Great Harwood at around 7pm on Tuesday, April 28.
Gary Drinkwater, watch manager at Hyndburn fire station, said the fire was started in a seating area next to the pavilion.
He said: “No damage was caused but it was definitely deliberate as they have piled up twigs to make a camp fire.
"They have gone by the time we arrived.”