An Islamic State manifesto for jihadist brides warns that girls should be married from age nine and women should be banned from study at university because it has “no worldly use”.

The lengthy document, posted to a jihadist forum by the Islamic State’s female militia Al-Khanssaa Brigade, was translated by the Quilliam Foundation, a counter terrorism think tank on Thursday.

The Women in the Islamic State: Manifesto and Case Study says girls should be married from the age of nine, and no later than sixteen or seventeen if they are “pure”.

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It laments the loss of women to secular society, claiming their fundamental function is “in the house with their husband and children”.

“Women gain nothing from the idea of their equality with men apart from thorns,” it reads.

“Many of our girls have been lost to secular society. They study things unrelated to religion and that have no worldly use.”

“Their studies last many years, stopping them from marrying until they reach completion of these strange studies.”

Women are told to be veiled at all times.

The document gives an insight into the life of women in the Islamic State’s self-proclaimed caliphate, where they are banned from mixing with men and are told to remain veiled at all times.

“It is always preferable for a woman to remain hidden and veiled, to maintain society from behind this veil,” the manifesto reads.

The Al-Khanssaa Brigade criticised Western society for encouraging women to work and wear what they want, calling them “immodest”.

“The model preferred by infidels in the West failed the minute that women were “liberated” from their cell in the house.”

“The falsity of these ideas were made evident by governments giving salaries to those who return to their homes and raise their children, finally openly accepting that they are ‘housewives’.”

The Quilliam Foundation said the manifesto gave an insight into the life of women in the Islamic State’s self-proclaimed caliphate.

“Much of what IS supporters claim on social media is designed to exaggerate, obfuscate and confuse,” the foundation said.

“It is fundamentally misogynist and, within its interpretation of Islamism, the role of women is “divinely” limited.”