Jano is 14, but yearns to feel like a child again. He wants to hug his mother, whom he hasn’t seen since he was 10 years old, the day Islamic State came to his village.

Jano is not his real name. A Yazidi boy from the village of Kocho, near Mount Sinjar in northern Iraq, he was kidnapped, indoctrinated and trained to become a boy soldier by Islamic State, or Isis.

About 400,000 Yazidis living in the area around Mount Sinjar were targeted by Islamic State in a “convert or die” campaign in the summer of 2014. The Yazidis were seen by Islamic State as subhuman because their ancient beliefs and traditions predate the major religions.

Jano was one of thousands of boys taken and trained to become jihadis. They were given new names, forced to speak Arabic rather than their native Kurdish dialect, and converted to Islam.

They told us we have three days to become Muslim or they would kill us all They were sent to camps where they were indoctrinated with Isis ideology and trained to kill. Very few have escaped.

Moments before Jano and his mother were separated, she passed him a telephone number that would save his life. He didn’t know whose number it was but he clung on to it throughout his indoctrination, eventually gaining enough freedom to buy a mobile phone, dial the number, reach his only surviving brother and escape.

Having spent about three years in Isis hands, Jano is speaking to The Irish Times some months after his escape, in a camp for Yazidi refugees where he now lives with his brother and a number of female cousins, in northern Iraq.

In the short term, he hopes to get a job in the city of Dohuk (to repay the $10,000, or €8,211, used to secure his escape). In the long term, he wants to reunite with his mother, who escaped Isis captivity much earlier and is receiving psychological treatment in Germany, like many Yazidis.

The massacre at Kocho stood out among the massacres of Yazidi towns because a video emerged online of Isis militants ripping young girls away from their families one by one. The video captures the terrifying shrill in the people’s screams.

It began when Isis surrounded Kocho and delivered an ultimatum to about 1,100 remaining Yazidis still trapped inside.

“They told us we have three days to become Muslim or they would kill us all,” Jano says, but “our people didn’t want to convert. After our three days finished, Isis seized Kocho and collected all the people in the school.

Jano’s mother was taken, as was his sister, who ended up in the hands of an Isis emir (a high-ranking military commander).

Training camp Jano was first sent to Tel Afar, a city north of Mosul, and then to a training camp for children.

A much younger Jano can be seen in several Isis propaganda videos from the time, showing children performing military exercises and drills. They became known as “cubs of the caliphate”. Other videos show children other than Jano executing prisoners at point blank range.

Their training consisted of indoctrination in Isis ideology, physical training and weapons training – small arms, assault rifles, heavy machine guns, rocket propelled grenades and explosives.

“The bombs they taught us to make could be made from C-4 [and could] destroy and erase an area of 10 square metres.”

Isis leader Abu Bakr al-Baghdadi preaches during Friday prayer at a mosque in Mosul. File photograph: Al-Furqan Media/Anadolu Agency/Getty Images Jano is calm as he recounts these experiences. Every now and then, he hesitates at the use of Arabic in conversation, clearly preferring not to use the language he was forced to adopt for three years.

He is physically developed compared with his peers in the camp for Yazidi refugees; he has been overexercising for some years. But he says the most difficult part of his training was his indoctrination in Isis ideology “because they were brainwashing us, putting another idea into our minds which was all about killing and madhhab and sharia [law]”.

“Our days were like this. In the early morning I would wake up and wash my face, then change my clothes for weapons training. After that, sharia training. Finally, sleeping early. All of our days were spent like this.

“But always before I went to sleep, I was practising the number that I had from my mom. I was always repeating it in my head to not forget it.”

Jano felt sure the number he was repeating to himself, “the last thing from my mom”, would lead to his rescue. Even though he didn’t know whose number it was, he knew it was something genuine while everything about Isis was false. It saved him mentally as well as physically.

He refers to other children whose minds succumbed to the indoctrination. “All of those children they are dangerous, a risk for all of the world. They have a dark future if they don’t get help; those children must be saved,” he says.

After 1½ years at the training camp, Jano was allowed to visit his sister, who was still bonded to the Isis emir. An adult guardian accompanied him.

“While I was staying with my sister I asked her who was this man she was staying with and she answered, ‘He is a big Isis emir, he comes after Abu Bakr al-Baghdadi.’” Al-Baghdadi is the elusive leader of Islamic State, who has made only one public appearance, on the occasion the group declared its “caliphate” in a mosque in Mosul in July 2014.

“Then I saw a photo hanging on the wall who was familiar to me because he was visiting our camp frequently. I asked who is he, and my sister answered, ‘Be silent and don’t talk about him, he is Abu Bakr al-Baghdadi.’”

These purported sightings would place the Isis leader as having frequently visited training camps for children, underlying the importance of future generations to the Islamic State leadership. Al-Baghdadi, who has a $25 million (€20 million) US bounty on his head, is believed to be alive and hiding in the desert region of Iraq and Syria, where Islamic State remains today.

I need to see my mom, I need to hug my mom After about a month with his sister, Jano was sent to the frontline in Syria to fight Kurdish forces near the Turkish border.

“There was no mercy. Anyone we passed, we killed, whoever they were [Shia, Christian, Kurds, etc], except Sunni people.” Sunni Muslims, he says, were offered the chance to pledge allegiance to Islamic State and if they didn’t, they were killed. Everywhere, he says, the men were killed and women and children made to pledge allegiance.

The Irish Times has seen photographs of Jano holding weapons as big as he is, draped in bullets, sometimes in front of the group’s infamous black flag.

Militant guardians Eventually he was sent to a factory for repairing broken and dirty weapons, in Raqqa, Syria, when it was under the group’s control. Here, he gradually gained the trust of his militant guardians.

“After that, they give me the paper of my freedom” – a permission slip which allowed him travel between certain checkpoints and explore his surroundings. “I went to buy a motorcycle [because] with that I could travel around and I would get to know places around me better.” It was at this point he was able to buy a mobile phone and call the number he had memorised for three years.

“First time no answer. I tried another time, and this time my brother answered me and when I heard him my eyes were full of tears, I was so happy.

“I told him ‘save me’ and my brother went to the [Bureau for the Rescue of Abductees, in Kurdistan],” which, along with his brother, organised his escape through middle men and smugglers, at a cost of about $10,000.