Islamic State has reportedly put a ban on its members selling sex slaves after some Yazidi women who were held captives were bought and then reunited with their families. 

Isis has issued a statement to prevent the sale of women captives, whom it refers to as "sabayas", the Syrian Observatory for Human Rights reported. 

According to the Britain-based agency which is said to monitor the conflict in Syria, the new rule by Isis was put forth after two Yazidi women were bought from an Isis fighter by an Iraqi man who took them to their families. The man reportedly bought the women for $12,000 each. 

Islamic State has set up a systematic slave market in its territory, putting in place rules and fatwas on how the women should be treated.

Yazidi women are said to form a bulk of these sex slaves under Islamic State, with reports suggesting girls as young as 10 are often sold for a "packet of cigarettes". 

Isis has defended its use of captive women as sex slaves by claiming Islam allows Muslims to rape non-Muslim women and use them as sex slaves. 

Yazidi women who escaped from the terror group have shared horrific accounts of rape and torture under Isis.