UNID Spanish Language 6920 kHz LSB 1315 UTC 3 Oct 2017

[R4002]

6920 kHz LSB
6.920 MHz LSB

While 6900 kHz LSB, 6930 kHz USB and 6994 kHz USB continue to be active...6920 kHz LSB popped up out of nowhere.  Two stations having a QSO, one of them has a very loud, and at times, overmodulated/clipping sounded signal.  A distinctive microphone "click", almost sounds like a very short duration end-of-transmission beep or "roger beep".  Several numbers read, including "0000" repeated three times by the stronger of the two stations.  At 1315 UTC, the stronger of the two stations was SIO 444.  Very professional sounding conversation, its possible that these aren't freebanders but are something else.  Discussing international events at 1316 UTC.