An Islamic State (Isis) rape victim has revealed that the terror group believes that a captured woman can be converted to Islam if she is raped by 10 of its fighters. The disclosure follows a UN report, which says the Isis has an estimated 3,500 people, mostly women and children from the Yazidi community, kept as slaves in Iraq.

The victim, whose identity has not been disclosed, said before she was raped, she was shown a letter which said a captured woman will become Muslim after 10 Isis fighters rape her. "Anyone who doesn't convert to Islam, we will kill the males and marry the girls. They are the spoils of war," the victim was told by IS (Daesh), according to the Express.

Defending its action, the IS said in the online magazine Dabiq: "Enslaving the families of the kuffar [unbelievers] and taking their women as concubines is a firmly established aspect of the Shariah [Islamic law] that if anyone were to deny or mock, he would be denying or mocking the verses of the Quran and the narrations of the Prophet."

A professor from Cairo's Al-Azhar University, Saud Saleh, reportedly also said that Muslim men can rape women captured during war. "The female prisoners of wars are 'those whom you own. In order to humiliate them, they become the property of the army commander, or of a Muslim, and he can have sex with them just like he has sex with his wives," Saleh allegedly said.

The alleged comments could be viewed by Isis as approval for keeping Yazidi women as slaves, Dr Andrew Holt, professor of history at Florida State College, said. "According to Isis, the practice of forcing the Yazidis and other religious minorities into sexual slavery is a way to prevent the sin of premarital sex or adultery, as well as a sign that the Final Battle will soon occur," Holt said.