Several years ago I witnessed several interesting lights at fairly low level over the Industial Areas of Teeside at night time. The lights were fixed Blueish White. One after another about 6 single lights flew from Teeside to overhead my appartment(3 floors up) at a place called Marske by the sea and then on to a place called Saltburn. Here they, in single file turned around and reversed their route back to Teeside. The lights were single with no other lights present and most strangely of all there was absolutely no sound whatsoever, even though the objects were directly overhead and low level???