Fire crews say they have seen a surge in blazes starting in bins against buildings in the centre of Leyland, with at least six fires within the last few weeks.
They say they have so far caused “moderate” property damage, but say it could only be a “matter of time” before the consequences become more serious.
Watch Manager Paul Rigden from Leyland fire station said one of the most recent fires was behind shops on Hough Lane, thought to have started overnight between Sunday and Monday this week.
He said: “We think somebody is deliberately setting fire to them.
“We would like to get a warning out to businesses and residents in the town centre to be a bit more vigilant and keep the bins secure and away from buildings.
“They are causing damage to property, and there is a life risk to people living above the shop if it spreads.
“There is only one fire engine in Leyland, so it’s taking the fire cover out of Leyland.
“So if there’s an incident elsewhere, potentially the residents would be waiting for an appliance from Chorley or Bamber Bridge.”
Fire bosses are now asking businesses to keep bins locked shut at all times and avoid over-filling, to secure bins away from buildings, and to avoid putting bins out earlier than the morning of collection.
Mr Rigden suggested the bins could also be chained to a fence, or to another bin, to make them more difficult to move next to a building.
He said the blazes had happened at least six times in the last three to four weeks, in the Hough Lane and Chapel Brow area. Call 101 or Crimestoppers on 0800 555 111 to report suspicious activity.