A deliberate fire was started at an old working men's club in Central Blackpool, say fire services.
Crews were called to the disused Central Club on Kent Road on Tuesday evening following reports of a fire in an outbuilding at the premises.
Firefighters say youths were reported in the vicinity of the club at around 6.30pm.
A spokesman for the service said: "The fire is believed to have been started deliberately and an investigation is underway.
"We think that some youths have managed to find their way into an outbuilding at the premises and started a small fire.
"The fire was around one metre in area and didn't do much damage, but there was potential for serious harm to come to these young people.
"There were gas cylinders in the yard and there were concerns that these could have become involved in the fire.
"If this had happened the consequences could have been far more serious.
"We are now trying to identify the people who were involved in this fire."
Fire crews spent around 30 minutes at the scene.
Nobody was injured in the incident.