Boys as young as 15 are being recruited to fight in the Yemen Civil War, with promises of financial compensation to their families when they are martyred, according to a report from Amnesty International.

The statement was prompted after the families of three boys approached Amnesty International to report that their sons had been actively recruited and sent to fight for Houthi rebels.

Recruitment of at least two of the boys occurred while they were attending a Quranic school in the Yemeni capital of Sana’a, which is currently under Houthi control following an uprising as part of the Yemeni Civil War.

According to interviews conducted by Amnesty International, these types of schools have historically become breeding grounds for fighters. Instead of traditional school subjects, young boys are being taught sermons and lectures extolling the virtues of war against the invading Saudi-led coalition. With the chaos throughout Yemen as a result of the civil war, the various armed groups and militias are able to further exploit deteriorating conditions and indoctrinate children to become soldiers.

In the case of these particular children, the boys had already been shipped to the Yemeni-Saudi border before their parents even knew of their whereabouts.

The UN has documented close to 1,500 child recruits, from all sides, in the Yemen conflict since March 2015.

The exploitation of children as soldiers is of course nothing new. Multiple organizations have given the issue international attention. The United Nations International Children’s Emergency Fund (UNICEF) has reported that a full one-third of fighters in the Yemen Civil War are children. Wars in Iraq, Sudan, Afghanistan, and the myriad brush fire wars throughout Africa between clans and warlords from groups like Boko Haram have all included child soldiers.

ISIS has stepped up the frightening exploitation and indoctrination of boys by using them to execute prisoners in highly edited and polished propaganda videos. The unfortunate reality of child soldiers is that they are easy to control, easy to manipulate, and provide a ready-made source of future fighters by giving them combat training, experience, and thorough indoctrination at a key developing point in their lives.