Two petrol bombs were thrown at a house in High Green, Sheffield.
Firefighters said the house was empty at the time of the attack and the flames were out when they arrived at 10.15pm on Sunday.
The two bottles, which were filled with petrol and then ignited, landed on the roof of an extension.
South Yorkshire Police have been alerted to the incident and are investigating.
The attack came a week after a petrol bomb was thrown into the living room of a flat on Longley Hall Road, Longley, Sheffield.
In that incident residents Collette Williams, aged 44, had to escape through a bedroom window.
She said she does not believe that she was the intended target but no longer feels safe in her home.
Anyone with information about the latest attack should call South Yorkshire Police on 101.