@ Saad: All satellites have big or small flat surfaces, such as solar panels. Since the satellites do not have a fixed orientation, the angle at which sunlight falls on them keeps changing. This causes almost all satellites (even military ones) to "flare", which is a rapid brightening and consequent dimming of the satellite. What you saw was a satellite flare.
There is a satellite flare, and then there is an Iridium satellite flare. Once you see it, you'll know what I mean. On Friday 15th October, go upstairs at 17:50 PST and lie down so that North is to your left. If the sky is Insha Allah clear, your view will be somewhat like this:
Keep watching, and then let us know what you see in the area marked by the white circle just left of the center. You should see the flare at 17:53PST, but if nothing is visible, keep a lookout for at least five minutes more. You may have come up early.
This is not anything rare and happens about six to seven (sometimes more) times every month. The above event is only for Rawalpindi/Islamabad and won't be visible in other cities.
For more satellite-related predictions: Heavens-Above Home Page
