Formation of initially 4 objects, one emitting another smaller object, then when witnesses gathered only three objects remaining.On this day, the 21st of August, 2010, I and three other people witnessed a formation of between 3 and five bright objects in the sky over Basel, Switzerland.I made the initial sighting while walking my neighbour's dog in the park behind my house, seeing 4 intensely bright white objects high in the sky to the south of my location. Initially I dismissed the objects as airplanes as Switzerland lying at the crossroads of Europe sees lots of air traffic. My initial assessment was deemed incorrect on the basis of other aircraft moving across the sky at altitudes that made it clear that they were indeed aircraft (shape, contrails, speed of movement). The four objects remained almost motionless, until I witnessed a smaller and less bright object break or drop away from one of the objects. At this point (after five minutes of viewing) I determined it necessary to gather other witnesses. I went into my house and asked my girlfriend to come outside with me, and to bring a camera. When we returned outside, the 4 objects were now 3 and we watched them for approximately 10 more minutes before going inside to look for another camera with! a telephoto lens. The objects moved slowly, and were hard to see against the brightness of the clear summer sky, often fading into the blue back ground and then returning with intensity in a new location making it difficult to judge their exact location. The objects moved closer to each other over time, one after the other, never at the same time. I stopped two other passing strangers to confirm that they could also see the objects, which after a moment of searching (again, bright white objects on a bright blue sky) they found and confirmed. At this point my girlfriend and myself went inside to look for my camera and telephoto lens. Upon returning outside the objects had vanished.Photos taken with the smaller digital camera reveal nothing of value.