Witnessed 5 circular objects in a "box" formation appear over local terrain feature, then accelerate away at extreme speed, followed by 5 more, that backed off.

At approximately 18:30hrs, I climbed out of the pool at our condominium complex. As I was towling off, I was looking approximately NNW, at "Windy Point"(a local terrain feature), when 5 objects appeared from the west, over the top of the Point. The objects came to a smooth halt, rigidly maintaining their formation. They were flying in a box formation --one at each corner, the fifth in the center. Their altitude would have been between 2000-3000 feet. The objects were disk-shaped, 30-50 feet in diameter, and emitted a 'soft-white' glow. As I watched, the objects underwent extreme acceleration, disappearing over the eastern horizon in seconds, while maintaining their formation. I looked back at the Point, and another group of five objects appeared, in the same formation. They came to a smooth halt, then 'backed up', the way they had come. At no time did the objects 'turn' in any way. They made no discernable sound. I later called the Edwards AFB PIO to report the incident, and was told that they were "...helicopters, on maneuvers." At the time of the incident, I was 11 years old. I susequently went on to join the USMC, where I served for 6 years. I have had an abiding interest in helicopters from a very young age, and I have never seen any helicopter perform maneuvers that even remotely resemble what I saw that night.