A derelict pub was set alight in Doncaster on Monday afternoon.
Adwick firefighters were called to the blaze on Shackleton Road, Clay Lane at around 2.30pm.
Initially, the incident was described as a small fire but it quickly spread and smoke was soon pouring through the roof of the building.
Crews wearing breathing apparatus used hose reels to douse the flames, leaving the scene at around 5pm.
Anyone with information about people starting fires deliberately should call Crimestoppers anonymously on 0800 555 111.