Hey Marius,
looks like a "fraternelle" medal. Those are unofficial medals made, by and for ,groups of old soldiers.
This "group" apparently started in 1941 and commemorated it in 1961.
Just need to figure out what FI/OF and PA/MP stands for. One must be Flemish and the other French.
My guess would be a resistant group initiated from some other organisation.
The light blue of the ribbon, makes me think "Congo", but it don't matches with the "FI/OF and PA/MP".....
No great values accorded to these medals, they can go from 10 to 30 euro....