Finally I found guys from Niger, 5U5R on 5360kHz QSX 5405kHz on CW at around 05:00UTC. I though that I will try at least catching my #69 on 60m band CW only. The pile-up was not so huge and the signal from 5U5R peaked 579 so I started to call them.
Well, what I can say... Thank you very much for QRM. I know "nobody is perfect".
Hope to work them next time.
73 - Petr, OK1RP