An alert witness and the quick actions of police officers resulted in a lucky escape for two occupants involved in a house fire at Wandilo on Friday night.

Mount Gambier police responded to reports of a house fire on Wandilo Forest Road about 11pm.

A member of the public noticed the fire as he drove past the property and immediately alerted emergency services.

He stopped to try and raise the occupants of the home but was unable to make contact with anyone inside.

When police arrived, officers could see flames coming from the roof and immediately forced entry to the property.

A man and woman were found sleeping inside and were unaware of the fire that was taking hold.

A number of CFS and MFS units attended as the fire spread to two vehicles and a boat parked underneath a carport.

Two firefighters and a police officer were treated at the scene by SAAS for minor smoke inhalation, and the two occupants were taken to the Mount Gambier Hospital as a precaution.

The cause of the fire is yet to be determined and Police Fire Cause Investigators on Saturday visited to the scene.

Anyone who witnessed the fire or may have seen any suspicious activity in the area is asked to contact Crime Stoppers on 1800 333 000.