Arab slave trade

Arab slave trade refers to the practice of slavery in the Arab world. It took place mainly in Western Asia, North Africa, Southeast Africa, the Horn of Africa. It also included parts of Europe (such as Iberia and Sicily), beginning during the era of the Muslim conquests and continuing into the 20th century. 
The Arab slave trade was conducted through slave markets in the Middle East, North Africa and the Horn of Africa. Most of the slaves were from Africa's interior.
Historians estimate that between 650 AD and the 1960s, 10 million to 18 million people were enslaved by Arab slave traders. They were taken from Europe, Asia and Africa across the Red Sea, Indian Ocean, and Sahara desert.
History.
One of the oldest slave trades in history was the Arab trade of Zanj (Bantu) slaves in Southeast Africa. This trade began 700 years before the European Atlantic slave trade. Men taken as slaves were often used as servants, soldiers, or workers. Women and children were mainly used as servants and concubines. 
Most male slaves were castrated. It is estimated that as many as 6 out of every 10 boys bled to death during this process. Even so, castrating slaves was worthwhile because eunuchs sold for high prices. Over time, the Arab slave trade shifted to concentrate more on women and young girls for sexual purposes. This was different than the later Atlantic slave trade, which concentrated on enslaving men for labor.
Modern slavery in Africa.
In Mauritania slavery was abolished legally in 1980. But Muslim Berbers still own an estimated 90,000 African slaves. This is despite the fact that African Mauritanians converted to Islam over a hundred years ago and the Qur’an does not allow Muslims to enslave other Muslims. Slaves are used for farm labor, concubines and domestic servants. The children remain the property of their masters. They can be bought, sold, or exchanged for trucks, camels or guns. 
Slavery in Sudan is active again with the Muslim north waging war against Animists and Christians in the south. In these raids almost all slaves are taken from the tribes in the Nuba Mountains. Government sponsored Arab militias often kill the men and enslave women and children. Those taken slaves are forced to convert to Islam. Those that refuse are put to death. The trafficking in women and children in Western and Southern Africa violates the 1948 UN Universal Declaration of Human Rights.