Considering the area that you were residing in, Occam's Razor would lead us to the conclusion that it is secret military stuff being tested, although not so stealthily! Most people these days don't seem to notice anything around them due to the mass use of smartphones etc, so maybe they factor that in to the testing. You definitely saw something and know through experience that it wasn't 'normal'. I have an open mind in these matters so it might well have been something 'other'. If I may ask, had you consumed anything that might alter the way you might perceive visual things ?