A man needed medical attention after a small fire at a house in Cedric Road, Edenthorpe, last night.
Fire crews were called at 8.40pm but the fire on a tbale was already out and the man was led to safety.
A fire service spokesman said it had been started dleiberately.
Doncaster firefighters were also called to Ellerker Avenue, Hexthorpe, just after midnight when an industrial wheelie bin was set alight and the flames spread to a fence and tree.
Hay bales at Priory Farm in Hampole were also set alight deliberately around 7.45pm yetserday.