Firefighters raced to a block of flats in Sheffield after a bed base was set alight in the lobby.
The blaze on Callow Mount, Gleadless Valley, was discovered at 11pm last night.
Crews managed to extinguish the flames without having to evacuate residents.
Yesterday morning they dealt with three vehicles set alight in arson attacks, including one car found engulfed in flames in a field on Marian Crescent, Askern, Doncaster.
The other cars were torched on Stanley Road, Chapeltown, Sheffield and Crowder Avenue, Southey Green, Sheffield.
On Saturday afternoon a derelict terraced house was also set alight.
The blaze, which was reported at 1pm, started in the lounge.
That same afternoon a car was torched on Woolley Wood Road, Shiregreen, Sheffield.
On Friday night a Volkswagen Golf was torched on Gaunt Way, Gleadless Valley, Sheffield and a derelict outbuilding was set alight on Carr House Road, Hyde Park, Doncaster.
Anyone with information should call South Yorkshire Police on 101 or Crimestoppers on 0800 555111.