SYDNEY (AFP) - A tornado ploughed through a rural area west of Sydney on Thursday (Sept 30), damaging homes and scarring a tract of countryside.

The Bureau of Meteorology said the tornado formed west of Australia's largest city, damaging a broad area near the town of Bathurst.

"There are reports of damage to houses, power lines and trees," the bureau said.

"From current reports, we have indications of damage over a 25 to 30km line, running roughly north-west."

The region had been on high alert for severe thunderstorms throughout much of Thursday.

Tornadoes are relatively common in parts of Australia, but rarely cause fatalities.

New South Wales State Emergency Services said warnings were ongoing and told residents to "secure or put away loose items around your house and balcony".