RAQQA, Syria – Mohammed, a 14-year-old from Raqqa, found himself in Ashbal al-Ezz, an Islamic State of Iraq and Syria (ISIS) indoctrination camp in Tabqa in rural west Raqqa province. There he learned the group’s ways and was trained for battle.

The camp is not like most others established by the Sunni militants in Syria – this one is specially designed for boys 15 and under.

“I went there to learn the Quran and the foundation of our religion,” he says. “ISIS said this was the purpose of the camp.”

The international Criminal Court in the Hague designates the recruitment of children under 15 years of age – or having them participate in active combat operations – as a war crime. The U.N. Convention on the Rights of the Child mandates that governments work to prevent the recruitment or combat use of children, nearly always boys, under age 18.

But activists and residents in Raqqa province say ISIS, which governs here with an iron fist, has been blatantly recruiting children at Ashbal al-Ezz, or the Cubs of Pride. Mohammed and other recruits stay for 25 days, becoming indoctrinated into the methods of ISIS’s particularly extreme version of jihad.

“When I arrived at the camp, fighters and religious teachers from the organization supervised our training,” Mohammed says. “The training was divided into two parts. In religious classes, they taught us their version of Islam, the extremist methods they follow, and the necessary foundations of creating an Islamic caliphate state – their ultimate goal. They also try to convince us of jihadist ideology, like the greatness of martyrdom.”

The second part of training is for combat. “They trained us very harshly,” he said. “They trained us to deal with being tired and to face hardship. They also trained us to use arms.”

Yasser’s father said officials from the militant group had tricked him into bringing his son to the camp by telling him it was merely for studying the Quran and foundations of Islam.

But when his son arrived, “It turned out to be a camp to recruit children to be a new generation of extremists. They were trying to prepare children to carry out martyr bombings on behalf of the organization. I did not accept that and tried to pull Yasser out of the camp, but they refused and prevented me from seeing him. They even threatened to execute me for attempting to prevent jihad.”

Ahmad al-Bakri, a media activist from Raqqa, says that since it took back control of Raqqa in early 2014, ISIS has been staging training camps to teach religious beliefs and combat skills to both adults and children. He said the group often bribes young men into attending, or uses rhetoric during the recruitment process that stirs teenage boys’ anger and desire to fight “the enemy.”

Bakri says ISIS recruits these children and young men by telling them that “fighting the enemy,” as they refer to non-ISIS groups, can only be achieved by attending a camp and learning how to “fight and worship.”

“It’s a system,” Bakri says. “They want to create generations of extremists to let their ideas and methods grow in our country.”

But Abou al-Ghanem, an ISIS fighter who trains children in the camps, says that his organization creates them merely “to fulfill the duty upon us all to fight the enemy and learn the foundations of jihad and the true teachings of Islam.

“We are teaching children who are less than 15 years old how to fight and use arms in order to build a generation of strong fighters who follow the righteous path,” he says. “That’s why we created these camps.”

Edited by Karen Leigh.