Mosul: Islamic State militants have burned alive at least 19 Yazidi girls, who were captured as ‘sex slaves’, for refusing to sleep with Jihadis in Central Mosul, Iraq.

According to reports, ISIS militants put the women in iron cages and set them on fire as punishment.

Eyewitnesses claims the horrifying mass execution of the young women took place in front of hundreds of people.

Read: Girl burns herself to be less attractive for IS: Ghastly tale of Yazidi woman

“The 19 girls were burned to death, while hundreds of people were watching. Nobody could do anything to save them from the brutal punishment,” an eyewitness told ARA News in Mosul.

"They were punished for refusing to have sex with ISIS militants," a local media activist was quoted as saying in the report.

Read: ISIS sex slaves forced to undergo two-finger virginity test: HRW

It is estimated that about 3,000 to 5,000 Yazidi women and young girls, including minors, are enslaved by ISIS and are experiencing unspeakable horrors.

Islamic State militants consider the Yazidis to be devil-worshippers. The Yazidi faith has elements of Christianity, Zoroastrianism and Islam. Most of the Yazidi population, numbering around half a million, remains displaced in camps inside the autonomous entity in Iraq's north known as Kurdistan.