And these are the 'good guys'! Sickening video shows US-backed Syrian rebels taunting and then brutally beheading a young boy because he was a 'spy'

• WARNING: GRAPHIC CONTENT 
• Nour al-Din al-Zenki thug decapitates boy accused of being a child soldier
• Boy was arrested for being a spy for government-supporting group al-Quds
• Fighters laugh and joke before beheading the boy in the back of an SUV
• Executioner shouts 'Allahu Akbar' meaning 'God is great' after killing child 

Fighters from a US-backed Syrian militant group have been filmed brutally beheading a child as young as 11. 

The video captures Nour al-Din al-Zenki fighters in the back of a truck with a child they claim is an al-Quds soldier supporting Assad's Syrian forces.

One of the fighters shouts 'Allahu Akbar' meaning 'God is great' after taking a small knife to the boy's throat and cutting off his head in the Palesinian refugee Handarat Camp in Northern Aleppo. 

The child, who is clearly under the age of 12, was arrested by the Islamist militants for allegedly being Palestinian Liwaa Al Quds, al-Quds Brigade fighter, according to Russia News Now.

Sickening footage shot immediately before the boy is slaughtered shows him in ragged clothes surrounded by bearded militants in the back of a pick-up truck. 

One of them holds him by the hair and slaps him in the face. 

Judging by his ragged clothes and the marks on his arms, it appears the boy was impoverished and may have been tortured before he was murdered in the video, seen by MailOnline. 

The boy is placed face-down in the back of the truck with his arms tied behind his back when the executioner is handed a small knife by a fellow fighter. 

He then cuts the boy's throat before shouting 'Allahu Akbar' and holds his head aloft.

Before the video ends, he places the head on the boy's back before jumping down from the SUV.  

Liwaa Al Quds is a pro-Syrian government Palestinian paramilitary faction made up of the Palestinians who have been driven out of their homes in the Handarat Camp once Islamist militants took over the neighbourhood. 

Today, the group is fighting alongside the Syrian Army to retake the camp.

Nour al-Din al-Zenki is part of the Levant Front, and its allies the Islamic Front and the Free Syrian Army are fighting to overthrow the Assad regime. 

It is also battling ISIS and the U.S government supplied the group with money and anti-tank missiles.