Chetniks, Bandits, and Cultists.... Oh My!

Heres a picture of some 'Chetniks' from Yugoslavia.  Im not sure when this picture was taken - but the Chautchaut machine gun piqued my interest, and I cant help but think that they look like a splendid group of bandits, or perhaps they're cultists, or they're in the employ of cultists trying to impede the players?