Youths are being blamed for causing a spate of rubbish and wheelie bin fires.
Firefighters were called to four separate incidents in Accrington in 90 minutes on Saturday.
The first rubbish fire started on Hyndburn Road at 8.15pm followed by another at the back of Peel Park at 8.45pm.
A wheelie bin was then reported to being on fire on Lodge Street followed by another rubbish fire round the corner on Spencer Street.
Watch manager Glenn Fogarty said there was no damage caused to properties and believes the fires were started by youths. Police said they are now investigating.