Indicator flashing automatically after car is stopped and door locked

In my ford falcon ba xt 2003, when I turn off the engine and lock the door. The indicators starts blinking one side at a time after a while. It blinks for 10-15 times and than stops, and then starts again after a few minutes. I recall seeing this oscillating blinking once while I was driving. This is turning out to be a very annoying problem. Could this be related to some sort of security feature, if so, how can I turn off this feature. Any insight into this would be highly appreciated