Police are investigating several fires in the Aldinga area overnight that damaged two cars.

Police and fire crews responded to reports of a car fire in a car park on Port Road, Aldinga about 12.30am on Saturday 24 December.

The Volkswagen was well alight, and the fire was extinguished by fire crews.

Just before 2am, while investigating that fire, the patrol spotted smoke in the distance and went to investigate.

They found two fires in Lacey Drive, Aldinga Beach; grass burning along the fenceline of a business and a car alight.

The Holden sedan was also destroyed.

Both fires were extinguished before spreading to nearby businesses.

Southern District CIB detectives and crime scene investigators attended and examined the fire scenes overnight.

Investigations are continuing.

Anyone who saw or heard any suspicious activity in the area last night or has any information about the fires is asked to contact Crime Stoppers on 1800 333 000 or online at www.crimestopperssa.com.au

Police urge the community to be vigilant about the risk posed to lives and property by fire this summer, not just in the Adelaide Hills and country regions, but also across the metropolitan and outer suburban areas.

Anyone who sees suspicious or reckless behaviour that increases the risk of a bushfire should contact the police assistance line immediately on 131 444.