Children as young as 9 are being added to a terror watch list by Dutch authorities who fear they may have been indoctrinated while living in Islamic State territories.

The Netherlands’ General Intelligence and Security Service (AIVD) is now classifying children who received combat training as national security threats, Dutch Daily deVolkskrant reported Wednesday.

The news comes two days after AIVD head Rob Bertholee stated at a briefing in Berlin that approximately 250 Dutch nationals including 60 women and 70 children have left the Netherlands to join ISIS in Iraq and Syria.

Women living under ISIS control are “expected to marry and have children as soon as possible,” according to an AIVD assessment published in January.

“Another important task for women is the recruitment of other women, often family members or friends. Some are also active in the Al-Khansaa brigade.”

The Al-Khansaa Brigade, the Islamic State’s all-female religious police, is largely made of foreign jihadist women from North Africa, Europe and other Persian Gulf countries, and 60 of them are believed to be from the United Kingdom.

The Islamic State has systematically used children both in active jihad and in recruitment practices, encouraging many of them to leave their families and join the Caliphate.

Fighting alongside adults, children under ISIS control attend child soldier training facilities and are used to carry out executions and suicide bombing missions.

In social media posts seen by The Foreign Desk, members of ISIS often share lists of items necessary to “make hijrah,” a term used to describe a holy migration to/for Allah in their messages, giving teenagers step-by-step directions on how to make the trip.