Darien police say they're investigating a rash of car burglaries that happened overnight in Noroton Heights.

Police issued an alert to residents Thursday morning reminding them to protect and lock up their belongings. They say there have been an unusual number of car break-ins in the area. Items such as GPS units, iPods and loose change were stolen from cars that were unlocked.

Darien Police Capt. Fred Komm says even if motorists do lock their cars, it doesn?t guarantee they won?t be entered by force, but he reminds residents that car break-ins are a crime of opportunity.