V formation doing "swarm of bees" manouversThis was the only UFO I have seen in my life and at the time I didn't believe in their existence; also it happened where I least expected, in a full-blown city.We lived in a house at the time and at about 20:00hs my mother prepared to go to the terrace to pick up our clothes, so I tell her to wait as I would get my binoculars (7x50) and enjoy a small observing session with her (astronomy is my hobby). When we got there, she was the one who first saw the object and said "What is that!?", I promptly turned and saw a Delta formation with 10 to 15 lights rapidly climbing on the East, their lights have a distinct blue color and appeared to be travelling very high with no sound. At first I thought they should be some sort of military aircraft, but then they started an incredible manouver with all the lights mixing with each other like a swarm of bees, my mother just said "Ooohhh!!" and I felt a strange feeling of facing an unearthly reality, I've just keep thinking "This was not done by humans". The crafts continue passing overhead and I pointed the binoculars at them, nothing more could be seen, only points of lights with maybe a little haze around them (but it could be the focus because I was really excited). I would like to point out that I couldn't figure out if it was a single triangular object with lights on its bottom side or if they were distinct objects; anyway as the crafts continue they slowly changed light color from blue (rising east) to blue-green (overhead) to a fiery red as they approached the West horizon. The apparent size of the formation was 1 degree (2 full moons) and their intensity approached -1 magnitude. I have managed to watch two more manouvers through binoculars (really incredible) and each of those manouvers lasted for about 3 seconds, after that all lights returned to their original positions instantly.No news appeared on local television or newsapaper although someone else should have seen the objects.The apparent velocity was very similar to a low earth orbit satellite, but I have no clue about their real altitude or velocity, the lights didn't blink at any time.((NUFORC Note: Date in June 1983 is approximate. PD))