Police are investigating a suspicious fire at Port Noarlunga South.

About 5.45pm on Sunday 28 July, police and fire crews were called to Honeyeater Avenue, after reports that a house under construction was on fire.

MFS crews extinguished the blaze which caused minor damage to the property.

Police want to speak to two male youths who were seen in the vicinity of the fire.

One is described as being of Caucasian appearance, aged between 14-16 years old with long blonde hair.

The other boy is described as being of Caucasian appearance, aged between 14-16 years old and was wearing a black beanie. Both left the area on bicycles.

Anyone who may have witnessed the incident is asked to call Crime Stoppers on 1800 333 000, or online at www.crimestopperssa.com.au