Whistling Sounds at Night in my area

In Panchkula, around my area, whistling sounds are heard during night, like yesterday it was around 12:45 am but today i just heard it at 10 pm only. I've been hearing these sounds for a long time, more than a week. and every one in my family has heard them too. And it's not the whistling sound of cooker or anything, just loud whistling sounds come at intervals of 5 minutes for 3-4 times and then it stops. Anyone has any idea what it is or what it could be?