Arsonists are being hunted by South Yorkshire Police following a series of blazes over the weekend.
A derelict industrial unit in Stopes Road, Stannington, Sheffield, was set alight at around 10.10pm last night.
Firefighters found old books, files and paperwork burning.
Crews in Sheffield also dealt with a shed torched in Woodhouse Lane, Beighton, last night.
On Saturday night a Ford Focus was torched in Beresford Road, Maltby, Rotherham and a shed was found burning in Christchurch Road, Doncaster.
Tyres and a tree were set on fire in Doncaster Road, Kirk Sandall and a front door to some bedsits in Whybourne Terrace, Wellgate, Rotherham, was also set alight.
Firefighters also dealt with an abandoned caravan torched in Tickhill Road, Bawtry, Doncaster and a pick-up truck fired in Silverdales, Dinnington, Rotherham.
Two hay bales were also set alight in Old Mill Lane, Barnsley, over the weekend.
On Friday night a motorbike was torched in Angleton Close, Manor, Sheffield and cars were set alight in Lodge Lane, Braithwaite, Doncaster and Green Moor, Barnsley.
Anyone with information should call South Yorkshire Police on 101.