They knew they would be severely punished for refusing to obey orders. Despite this, two child soldiers of the Islamic State (ISIS) bravely dared to refuse a direct order from their superiors for them to carry out the execution of two civilian captives.

The punishment for disobedience could be considered "lenient" in ISIS terms—the two loss only their hands, not their heads.

In a sketchy report with an accompanying photo released on Thursday, Iraqi News said "members of the Islamic State terrorist group amputated the hands of two children, for refusing to carry out the execution sentence on two civilians in front of their families."

Citing a local source, the Iraqi online news outlet said the two children who were meted the hand amputation punishment were aged 10 and 12 years old.

They were part of a group of children based in ISIS camps in Nineveh, Iraq, the report said.

These "Cubs of the Caliphate" have been featured in ISIS propaganda videos carrying out executions of the jihadist group's captives.

In December 2016, an apprehended would-be suicide bomber described how the ISIS leadership is training children to fill the group's depleted ranks as their fighters come under relentless attacks from Iraqi and other coalition forces.

The 15-year-old Iraqi boy named Mahmoud Ahmed had second thoughts in carrying out a suicide mission in Kirkuk, Iraq in August last year. He was subsequently arrested by Kurdish forces.

Ahmed confessed that he was one of dozens of other children who were being indoctrinated in jihadist doctrine and trained as young warriors.

Kurdish intelligence officials said there are thousands of other children across Iraq and Syria who are being trained by ISIS to fight and carry out suicide attacks. Some of the children are as young as nine years old, the officials added.

One of the officials said ISIS is using child soldiers because they are harder to detect by enemy forces and because they are also easily duped.

In November 2016, ISIS released a video showing children and pensioners being forced to carry out executions of prisoners.

The video also showed ISIS leaders crucifying alleged traitors in a bid to terrorise the remaining population under their control.