Lights in Line Abreast Formation traveling independently

A formation of 10 circular lights traveling line astern, not all equally spaced and appearing to move independently, on a northwest to southeast course flying over Lake Forest, CA near Civic Center. Maintained visibility for approximately 5 minutes before disappearing into the horizon. Confirmed whether there were aircraft or helicopter activity near my position and these targets were not visible on The FlightRadar24 Application at my location or on observed flight path.