But Nasir, not his real name, was one of dozens of youngsters - some just five years old - who have managed to escape from Raqqa, and tell reporters of how the extremist militants ordered them to murder their own parents.
IS fighters tried to brainwash the children into believing their parents did not care for them as much as they once did - and that their first task was to return home and kill their "unbeliever" parents.
"There were 60 of us. The scariest time of all was when the airstrikes happened. They'd lead all of us underground into the tunnels to hide. They told us the Americans, the unbelievers, were trying to kill us - but they, the fighters, they loved us, they would look after us better than our parents," Nasir told CNN.
Nasir was able to escape the training camp and now lives with his mother in a refugee camp in Kurdistan.
Seeing his mother again was "like coming back to life", the boy said.
IS militants have kidnapped and enslaved many young boys and girls - a new UN report says IS holds as many as 3,500 women and children as slaves.
There have been many reports about how IS militants would snatch boys from their families and train them to become child soldiers and suicide bombers to fight their wars on the adults' behalf.
|The scariest time of all was when the airstrikes happened|
Children are trained by IS
to become killers [via social media]
Ali Saqr, a 21-year-old forced recruit, was earlier this month reportedly ordered to kill his mother, 45-year-old Lena al-Qasem, in public, after she told him the US-led coalition would "wipe out" the IS group and for trying to convince him to flee Raqqa with her.
Other reports said that she had gone missing after being accused of spying for the Syrian regime.
IS is showing signs of desperation and the group's brutality seems to be working against them.
They are exhausting the patience of civilians and the support of their own fighters - who are murdered in public for the smallest deviation from the arbitrary and extremely strict rules enforced by the extremist group, which follows a perverse interpretation of Sunni Islam.
There are already many known defectors from the group and it has been reported that not many are willing to sign up to replace them.
|IS has ordered the halving of its fighters' salaries in Syria|
In a document that seems to have been released by the so-called Islamic State group's treasury, IS has ordered the halving of its fighters' salaries in Syria for "exceptional circumstances" as the US-led coalition and Russia have been bombing the armed group's supply lines, cash stores, and oil fields since October.
Boys who refuse to become "cubs of the caliphate" would be savagely punished, said children who managed to escape.
The boys would be indoctrinated into the radical group's brand of thought and taught to kill any "unbelievers", including their parents.
Nouri's life was saved when the group broke one of the 11-year-old boy's legs in three places for refusing to become an IS footsoldier.
When Nouri's leg healed, he was limping and the group allowed his grandmother to take him home.
His five-year-old brother was repeatedly beaten, utterly traumatised and suffered from seizures. He too was released by the group - but his infant brother and parents remain in captivity.