I was walking on Pileos str. in Ag.Dimitrios in Athens-Greece and I saw 2 bright flashing /pulsating UFO's, south -southeast from me. They were changing colors, formation and directions. They were also dissapeared and re-appeared several times. I was wathcing them for 10 minutes. I called some friends to ask if they saw them too, but no luck. After 10 minutes they just light off and vanished without a trace.