The Darfari are the people from Darfar. The Darfari are followers of the god Yog, and most take part in ceremonies involving human sacrifice and cannibalism. They file their teeth into sharp points, which gives them a sinister look.
In Zamboula, the Darfari are slaves to the people. Cannibalism is not tolerated there, but because of the vast amount of Darfari slaves, the higher class fear restraining their cannibalistic rituals in case the slaves revolt.
This makes Zamboula a dangerous place for strangers. At night, the slaves go out into the streets and hunt for their human prey. The local population are aware of this, and keep inside at night. They do not care much about what happens to the strangers that unknowingly wanders out into the streets at night.