Suspicious fire damages Dubbo school hall

A fire that broke out at a school hall in the central western NSW town of Dubbo is being treated as suspicious, police say.

A suspicious fire has damaged a Dubbo school in central western NSW but students will not be affected.

The blaze broke out at the back of the auditorium and spread to the roof before it was extinguished at about 11.30am on Sunday, a Fire & Rescue NSW spokeswoman said.

"Naturally we are very disappointed ... but we thank the fire brigade for their quick and effective response to the fire," Dubbo College Delroy Campus principal Debbie Head said in a Facebook post on Sunday.