The Islamic State is tightening its grip on the thousands of women and girls it's holding captive as sex slaves, making it increasingly more difficult for smugglers to help them escape.
Despite increased losses of territory, the terrorist group has been curbing efforts to free the estimated 3,000 predominantly Yazidi female sex slaves.
"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," The Associated Press reports.
"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."
The AP also noted that ISIS uses "encrypted apps to sell the women and girls" as well as "postings [that] appear primarily on Telegram and on Facebook and WhatsApp."
"Both Facebook-owned WhatsApp and Telegram use end-to-end encryption to protect users' privacy," continued the AP.
"Both have said they consider protecting private conversations and data paramount, and that they themselves cannot access users' content."
An extremist Islamic group that holds swathes of territory in Syria and Iraq, IS is widely known for its brutal terror attacks and other human rights violations.
This includes the capture and sale of thousands of non-Muslim Middle Eastern women and girls to become sex slaves for its militants.
The AP's report mirrors a Washington Post article from late May on the militants' use of social media to traffick women.
"Social-media sites used by Islamic State fighters in recent months have included numerous accounts of the buying and selling of sex slaves, as well the promulgation of formal rules for dealing with them," the Post reported.
"The guidelines cover such topics as whether it's possible to have sex with prepubescent prisoners — yes, the Islamic State's legal experts say — and how severely a slave can be beaten."
The AP's report on IS' sexual slavery comes as the jihadist group launches several terror attacks against predominantly Muslim targets.
During the Islamic month of Ramadan, IS has launched attacks in several major predominantly Muslim cities, including Istanbul, Baghdad, and Medina, the last of which is considered the second holiest city in Islam.
Earlier this week Saudi Arabia's top Islamic clerics denounced the attacks on Medina and other cities, saying that the perpetrators "violated everything that is sacred."