Story highlights Hanan, 19, was captured by ISIS when militants took the town of Sinjar

She was among the women and girls separated to be sold as sex slaves

The names in this report have been changed out of security concerns for Yazidi family members still being held by ISIS.

Duhok, Iraqi Kurdistan (CNN) In the canvas expanse of the Shariya refugee camp, thousands of Yazidis live within hearing distance of one of Iraqi Kurdistan's frontlines with ISIS.

The vast majority of the camp's occupants are from the town of Sinjar and fled the ISIS assault there back in August. But not everyone escaped. ISIS took thousands of Yazidis captive.

Men faced a choice -- convert to Islam or be shot. But the Islamist militants separated the young women and girls to be sold as sex slaves.

In its fourth edition of "Dabiq," the ISIS online magazine, an article titled "The revival of slavery before the hour," outlines the group's twisted justification and guidelines for the enslavement of the Yazidis.

"One should remember that enslaving the families of the kuffar (infidels) and taking their women as concubines is a firmly established aspect of Shariah," the article reads.

Photos: Yazidis flee ISIS Photos: Yazidis flee ISIS A small boy sits on the ground at Shariya refugee camp in Duhok, in Iraqi Kurdistan. It's home to thousands of Yazidis, many who fled from Mount Sinjar and surrounding towns when ISIS fighters moved in. Hide Caption 1 of 12 Photos: Yazidis flee ISIS Thousands of Yazidis from the town of Sinjar were taken captive by ISIS forces. Fighters separated the women from men and forced them to become sex slaves. Men faced a choice: Convert to Islam or be shot. Hide Caption 2 of 12 Photos: Yazidis flee ISIS While thousands of Yazidis were captured, thousands of others fled. Many ended up here in the camp, where you can hear the occasional reverberation of what are said to be airstrikes from the ISIS front line, around 30 kilometers (18 miles) away. Hide Caption 3 of 12 Photos: Yazidis flee ISIS Amid all the uncertainty, a woman carries out domestic tasks. Yazidis are of Kurdish descent, and their religion is considered a pre-Islamic sect that draws from Christianity, Judaism and Zoroastrianism. Hide Caption 4 of 12 Photos: Yazidis flee ISIS Children play in the dirt with toys crafted from cardboard. Some clamber through the wire fence and play with rocks -- anything to keep themselves entertained. Hide Caption 5 of 12 Photos: Yazidis flee ISIS The Shariya camp opened six months ago and now 4,000 tents line the dusty ground, providing shelter to thousands of refugees. Hide Caption 6 of 12 Photos: Yazidis flee ISIS A small child is seen within the safety of a tent at the refugee camp. It's not known how long they'll have to stay here. Hide Caption 7 of 12 Photos: Yazidis flee ISIS A man gives another a shave. For many, an element of normalcy has returned after months in the camp. Hide Caption 8 of 12 Photos: Yazidis flee ISIS Despite everything they've been through, some Yazidi refugees find a reason to smile. Hide Caption 9 of 12 Photos: Yazidis flee ISIS Many families were separated when ISIS forces raided Yazidi villages, mercilessly killing anyone who tried to escape. Hide Caption 10 of 12 Photos: Yazidis flee ISIS No one knows the reason why, but in early April, ISIS released more than 200 Yazidis . Many of them were women and children, others were ill or elderly. Hide Caption 11 of 12 Photos: Yazidis flee ISIS The Yazidis have long suffered persecution, with many Muslims referring to them as devil worshipers. The ISIS storming of Sinjar created a humanitarian crisis as some fled into the mountains and were trapped without food or water. Hide Caption 12 of 12