Before answering the question above, we should note that Muhammad -- the role model of the Muslims, the person whose life they regard exemplary -- himself owned black slaves! We read, for example, in this Sahih Bukhari hadith, "Narrated Anas bin Malik: Allah's Apostle was on a journey and he had a black slave called Anjasha..." (Sahih Bukhari 8:73:182, see also Sahih Bukhari 9:91:368, etc.).
EVEN TODAY, SOME MUSLIMS ARE STILL ENSLAVING AFRICANS.
A recent article notes that
Slavery in Africa Is Alive, Well and Ignored. We read that
in the Sudan, "Many of the slaves were Christians taken north and forced to convert to Islam or die. Their faces were branded."