The Africa Fund statement:

In Mauritania alone an estimated 100,000 men, women and children are enslaved. They are property to be inherited, given as gifts, forced into marriage and sexually abused. Anyone whose mother is a slave is born into slavery.

Brutality and torture are common. For "minor" offences slaves can be flogged with a wet cord or starved for days. Slaves who try to escape have been buried in the sand and covered with hot coals. When slaves grow too old and feeble to work they are often "emancipated" and left to die. Although slavery is technically illegal in Mauritania none of this is punishable by law.

Black Avenger Cave article Jeopardizing Farrakhan's enormous lie

...These included camel treatment. A slave is tied around the stomach of a dehydrated camel who then is given water to drink until its stomach expands and the slave is torn apart. ... They include the insect treatment, whereby bugs are put into the slave's ears, which are then sealed with wax, and the slaves are driven mad by insects inside the head.

Links:

CASMAS Mauritania Q&A

Simon Wiesenthal Center online petition to the Secretery General of the United Nations