Why don't we hear about arab muslims killing black muslims?

The relative indifference of the Islamic world to the plight of black Muslims is nothing short of breathtaking. While 300,000 Africans have lost their lives to Arab genocide in the past six years, the only Muslim protest has actually been in defense of their killers.

Of course no one is worried about this and if they are they just call it the genocide going on in Afica. Why is it never reported that arab muslims are killing the black Africans? I guess it is politically incorrect to do so.