Nineteen girls from the Kurdish Yazidi religious community were burned to death in iron cages by Islamic State militants in the Kurdish region of Iraq on Thursday after refusing to have sex with their ISIS captors, the ARA News website reported on Tuesday.

"The victims, who had been taken by ISIS jihadis as sex slaves, were placed in iron cages in central Mosul and burned to death in front of hundreds of people," the website stated, citing information from local media activist Abdullah al-Malla. "They were punished for refusing to have sex with ISIS militants,” Malla said.

“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.

More than 5,000 Yazidis, mostly women and children, were captured and enslaved by the militants when they overran the Sinjar area in northwestern Iraq in the summer of 2014, purging the minority they consider to be devil worshippers.

At of the end of last month, more than 2,000 Yazidis had escaped, been ransomed or were rescued, but the rest remained unaccounted for as of then.

Yazidi captives have been taken to towns and cities across the militants' self-proclaimed caliphate in Iraq and Syria, including their de facto capitals of Raqqa in Syria and Mosul in Iraq.