my father's AAK AAK unit was deployed in Kahuta mountains. during that time and he himself has said few times that they were alerted about the Israeli/Indian air raid at least on 3 occasions and at one time it seemed that the attack had already commenced and all anti Aircraft batteries and SAM systems were cleared to open fire.
the air raid sirens will sound the moment fighter jets were detected taking off from Indian side and approaching Pakistani airs space. the war was imminent for sure and on one of those near war situations when it was learnt that Satwant Singh had saved the subcontinent from yet another Indo-Pak war.
the military personal deployed to defend our nuclear sites know very well what happened back then and they dont need any "links" to prove the story right. they were pretty much part of the whole scene.
my office building conducts fire drill every 6 months.. there will be sirens and strobe lights. Once it was so real fire dept trucks were out and we were told to rush outside !! I am going to tell my dear son same story to emphasize how important it is to pay attention to safety protocol!