The news from Manchester is yet another example of an horrific trend from ISIS: the systematic targeting of adolescent girls and young women around the world. Ariane Grande is a popstar beloved by her fan base of mostly girls and young women. Children — almost certainly teenage girls — are among the victims of this attack. In choosing to target an Ariana Grande concert, the attackers knew exactly the kind of people they would be killing.

The targeting of teenage girls follows a disturbing pattern by ISIS. In August 2014, when ISIS militants were on the rampage in ethnically diverse parts of Iraq they separated young women and teenagers from the men and boys. The girls from the ethnic Yazidi groups were kidnapped and many enslaved and subject to sexual abuse. These attacks amounted to genocide, according to UN investigators. The UN investigators also concluded that the violence against girls is a central tenant of ISIS ideology and sexual enslavement of girls is a key tactic in their genocidal enterprise:

After capture, the Yazidi women and children were then divided according to the Shariah [religious law] amongst the fighters of the Islamic State who participated in the Sinjar operations, after one fifth of the slaves were transferred to the Islamic State’s authority to be divided as khums [spoils of war]…. The enslaved Yazidi families are now sold by the Islamic State soldiers as the mushrikin were sold by the Companions.

To this day, the UN says some 3,200 Yazidi women and girls remain in ISIS captivity.

One girl, though, managed to escape and tell her story. Nadia Murad was a teen when ISIS overran her town. She’s now a UN Goodwill Ambassador. She told the BBC how she managed to escape from daily sexual abuse by ISIS.

The point is, that ISIS targeted a show whose main concert goers were likely to be teenage girls. This was not a coincidence, but can be interpreted in the context of the terrorist group’s broader campaign against young girls.