The Islamic State (Isis) terrorists chopped off a hand and a leg of a 14-year-old boy in Syria after he refused to fight for the Sunni terrorist group, a new report said.

The Isis has been torturing children to make them fight for the group, NBC News, which interviewed several children who escaped to Turkey from Syria, reported.

The radical terror group cut off Mohammed's right hand and left leg as a punishment for trying to flee the training camp as he did not want to become a suicide bomber. A Sharia judge, during his trial, said that by choosing to leave the land of "true Islam" he was abandoning his religion.

"This is the judgement of God. You were going to the land of the infidels... so you are like them. Your leg and arm must be cut off," the judge told the young boy.

The boy, who now lives in the Turkish city of Sanliurfa, told the American broadcast network that on the day he was punished, the Isis invited foreign fighters and their children. They were made to sit in the front row. Amid loud cheering and celebration, an Isis militant amputated the boy's limbs, the report said.

The Sunni terror group, known for its "misguided Sharia interpretations", has been severely admonished by the United Nations for using mentally challenged children as suicide bombers. Similarly, a report by the UN Committee on the Rights of the Child published in February, accused the Islamic State of using children under the age of 18 to carry out suicide attacks.

Isis, which runs extensive military camps for children, trains them not only on how to use deadly weapons, but they are also forced to watch gruesome beheading and execution videos to desensitise them against such brutal practices.

According to UK-based Syrian Observatory for Human Rights (SOHR), the Isis used 52 child soldiers as suicide bombers in 2015 alone. The report emphasised that it had documented proof that the Isis is using children below the age of 16 as suicide bombers.