In this video a Yazidi teenager recounts the horror of being held as sex slave by IsisIBTimes UK

Jihadists fighting with the Islamic State (Isis) have turned to social media sites like Facebook to sell female sex slaves, it has been reported. The extremists have forced so-called 'sexual jihad' on thousands of captured women from Kurdish, Yazidi and Shite territories in the past two years.

Militants can buy and sell the sex slaves as they wish in the self-declared caliphate — with some women being handed over as prizes of war or to settle debts. Although Daesh (Isis) militants have to pay a small tax, the trade in sex slaves is a burgeoning part of the terrorist's economy.

Isis has even drawn up a set of rules to follow when trading sex slaves which allows for prepubescent girls to be sold. They say: "The inevitable consequences of the Jihad establishment is that women and children of infidels will become captives of Muslims."

Now it would seem they are taking the horrific trade onto social media with one cash-strapped jihadist offering a sex slave for around $8,000 (£5,500). A Facebook post by a fighter calling himself Abu Assad said a girl on sale was around 18-years-old.

According to the Washington Post, Almani, who is thought to be a German national, said: "To all the bros thinking about buying a slave, this one is $8,000". He then posted a second image a few hours later with a young girl being offered up as a sex slave, with the caption "yay or nay?".

Human Rights Watch believe that Isis have control of 1,800 women and girls whilst in April the UN estimated that the extremists were holding around 3,500 Yazidi women and children. Yazidis have been particularly abused as they are believed to be apostates by Isis who raided their spiritual home near Mount Sinjar, Iraq.

"We have seen a great deal of brutality, but the content that Isis has been disseminating over the past two years has surpassed it all for sheer evil," said Steven Stalinsky, the Middle East Media Research Institute's executive director to the post. "Sales of slave girls on social media is just one more example of this."

The posts were quickly removed by the social media platform and it is not clear whether or not he was selling the woman or was just referring to the sale. Social media sites have removed dozens of accounts used for the buying and selling of sex slaves in the last two years.

Members of the Yazidi
Yazidi women are subjected to abduction and systematic rape by Isis fightersReuters