Islamic State (IS) has published a shocking guidebook for its fighters on how to rape slave girls – even if they have not reached puberty.

The Arabic manual, titled Questions And Answers On Taking Captives And Slaves, instructs IS fighters on how to buy and sell women and girls who have been captured in war as booty.

The document, published by the Research and Fatwa Department of IS, gives its fighters the green light to turn captured women into slaves and concubines, and even give them as gifts to one another.

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ISIS fighters have taken thousands of women and children as captives, especially around 2,500 women from the minority Yazidi sect in Iraq (pictured)

It was circulated on the Twitter accounts of senior IS leaders and on Friday was distributed by masked IS fighters outside a large mosque in Iraq’s second city Mosul, which is controlled by the group.

The document has been obtained by the Washington-based Middle East Media Research Institute and translated into English.

British terrorism experts, who have studied the document, have concluded it is genuine.

They have condemned the manual – which answers questions dealing with sex with slave girls, their status as the master’s property, and how to beat them – as ‘disgusting’, saying it harks ‘back to the Dark Ages’.

In the guide, one question asks: ‘Is it permissible to have intercourse with a female slave who has not reached puberty?’

The response is: ‘It is permissible to have intercourse with the female slave who hasn’t reached puberty if she is fit for intercourse.’

The Arabic manual (pictured), entitled Questions And Answers On Taking Captives And Slaves, instructs ISIS fighters on how to buy and sell women and girls who have been captured in war as booty

A tweet by one of the group's leaders in answer to the question: 'Is it permissible to have intercourse with a female slave who has not reached puberty?'

Another asks: ‘Is it permissible to sell a female captive?’ The response is: ‘It is permissible to buy, sell, or give as a gift female captives and slaves, for they are merely property, which can be disposed of.’

The document says that all ‘unbelieving’ women, including Jews and Christians, can be taken as captives and sold as slaves. However, it prohibits the enslavement of Muslim women, even if they have become apostates.

The pamphlet allows masters to beat their female slaves, but only as a disciplinary measure, and not as a source of gratification. The master is also forbidden from beating his slave-girl on the face.

Haras Rafiq, an expert at British counter-terrorism think-tank the Quilliam Foundation, said: ‘It is a sick and disgusting document, and it takes the world back to the Dark Ages.

'There is no place for slavery in the modern world. There have been widespread reports of IS fighters raping female captives, which has now become part of the anti-IS propaganda.

'This document may be a way to regulate the behaviours of these fighters.’