Melbourne kindergarten gutted by fire

A Melbourne kindergarten has been gutted by fire after a blaze swept through an old South Yarra church.

Fire Rescue Victoria crews took about an hour to contain the fire in the early hours of Thursday morning at the old Presbyterian church on Punt Road. The emergency service confirmed on Thursday afternoon the blaze was caused by an electrical fault.

The building is the site of Christ Church Grammar School kindergarten.

Christ Church deputy principal Keith Newman said several rooms were destroyed in the fire but no one was injured.

"The staff are really devastated over it," Mr Newman told the ABC on Thursday.

"It's hit quite hard.

"Our kindergarten is a really beautiful part of our school ... and our families love coming here and so do our students."

A watch and act message for nearby residents has been downgraded to a warning over heavy smoke and traffic delays.

Christ Church Grammar will be closed on Thursday, as will the neighbouring South Yarra Primary School.

Fire investigators are working to determine the cause of the blaze.