Arsonists broke into a house in Mexborough, Doncaster, last night and set fire to it.
Dearne fire crews were called to the property in Albert Road at 8pm and found the living room wsa burned out.
The rest of the house was also affected by smoke and a fire service spokesman said the fire had been deliberately started.
A fire which destroyed 20 bales of hay in a field off Nutwell Lane, Armthorpe, was also started deliberately.
Firefighters spent three hours turning the hay over and extinguishing the flames.