One of my favorite words is “internecine.” Of course, I don’t admire the concept (i.e., hostility or conflict within a group). I just like the sound of its syllables clanging together.
In any case, “internecine” describes the situation whenever ethnic minorities beat up on each other. It’s most famous application is “black-on-black violence.”
I have yet to hear about brown-on-brown violence, but perhaps it is only a matter of time. For example, a few months ago in Staten Island, a Mexican immigrant became one of the borough’s recent victims of a hate crime.