The advertisement on the Telegram app is as chilling as it is incongruous: A girl for sale is "Virgin. Beautiful. 12 years old.... Her price has reached $12,500 and she will be sold soon."

The advertisement on the Telegram app is as chilling as it is incongruous: A girl for sale is "Virgin. Beautiful. 12 years old.... Her price has reached $12,500 and she will be sold soon."

While the Islamic State group is losing territory in its self-styled caliphate, it is tightening its grip on the estimated 3,000 women and girls held as sex slaves. In a fusion of ancient barbaric practices and modern technology, IS sells the women like chattel on smart phone apps and shares databases that contain their photographs and the names of their "owners" to prevent their escape through IS checkpoints. The fighters are assassinating smugglers who rescue the captives, just as funds to buy the women out of slavery are drying up.

The thousands of Yazidi women and children were taken prisoner in August 2014, when IS fighters overran their villages in northern Iraq with the aim to eliminate the Kurdish-speaking minority because of its ancient faith. Since then, Arab and Kurdish smugglers managed to free an average of 134 people a month. But by May, an IS crackdown reduced those numbers to just 39 in the last six weeks, according to figures provided by the Kurdistan regional government.

Mirza Danai, founder of the German-Iraqi aid organization Luftbrucke Irak, said in the last two or three months, escape has become more difficult and dangerous.

"They register every slave, every person under their owner, and therefore if she escapes, every Daesh control or checkpoint, or security force - they know that this girl ... has escaped from this owner," he said, using the Arabic acronym for the group.

U.S. State Department spokesman John Kirby told the AP that the U.S. continues "to be appalled by credible reports that Daesh is trafficking in human beings, and sex slavery in particular."

"This depravity not only speaks to the degree to which Daesh cheapens life and repudiates the Islamic faith, it also strengthens our resolve to defeat them," he said.

The AP has obtained a batch of 48 head shots of the captives, smuggled out of the IS-controlled region by an escapee, which people familiar with them say are similar to those in the extremists' slave database and the smartphone apps.

Lamiya Aji Bashar tried to flee four times before finally escaping in March, racing to government-controlled territory with Islamic State group fighters in pursuit. A land mine exploded, killing her companions, 8-year-old Almas and Katherine, 20. She never learned their last names.

The explosion left Lamiya blind in her right eye, her face scarred by melted skin. Saved by the man who smuggled her out, she counts herself among the lucky.

"I managed in the end, thanks to God, I managed to get away from those infidels," the 18-year-told the AP from a bed at her uncle's home in the northern Iraqi town of Baadre. "Even if I had lost both eyes, it would have been worth it, because I have survived them."

___

The postings appear primarily on Telegram and on Facebook and WhatsApp to a lesser degree, he said.

Both Facebook-owned WhatsApp and Telegram use end-to-end encryption to protect users' privacy. Both have said they consider protecting private conversations and data paramount, and that they themselves cannot access users' content.

"Telegram is extremely popular in the Middle East, among other regions," said Telegram spokesman Markus Ra. "This, unfortunately, includes the more marginal elements and the broadest law-abiding masses alike." He added the company is committed to prevent abuse of the service and that it routinely removes public channels used by IS.

In addition to the posting for the 12-year-old in a group with hundreds of members, the AP viewed an ad on WhatsApp for a mother with a 3-year-old and a 7-month old baby, with a price of $3,700. "She wants her owner to sell her," read the posting, followed by a photo.

"We have zero tolerance for this type of behavior and disable accounts when provided with evidence of activity that violates our terms. We encourage people to use our reporting tools if they encounter this type of behavior," said Matt Steinfeld, a spokesman for WhatsApp.

___

Lamiya was repeatedly raped by multiple IS members, one of whom was a doctor. Speaking to the news agency, the teenager said that she would have fled even if she was rendered blind in both eyes.

Another escapee, Nadia Mourad, had appeared before the U.S. Congress and the European Parliament seeking aid for the ailing community, which had once numbered in 50,000. Their population count is not known since Isis began its offensive.

The Yazidi people in Iraq are used not only as sex slaves, but also as human shields. NGOs working to rescue the people in captivity lament that despite victory over Fallujah or Ramadi, the girls are nowhere to be found when the terrorist group retreats.