The footage was purportedly filmed near the Iraqi city of Tikrit, where a coalition of 30,000 Iraqi Army soldiers and private Shia armies launched a campaign to oust ISIS militants earlier this week.

The horrific film has not been independently verified and could easily be just the latest piece of propaganda to be released by the terrorist organisation. Nevertheless the sheer brutality of the clip calls into question the policy of allowing local armed groups to lead the fightback against ISIS. 

 The video begins by showing a group of heavily armed men surrounding a young boy, who is forced to his knees and questioned about being an ISIS supporter.

'Did you not fire at us?' one man towering over the boy shouts, to which the helpless child replies 'By God I did not fire one single bullet.' 

The armed men plead to be allowed to execute the young boy, who begs for them to spare his life.

One soldier wearing camouflage trousers bravely steps forward and demands nobody shoot, asking 'What is wrong with you guys?', which leads to an argument among the men.

The militiaman is ordered not to stand in the way of the terrified child, who crawls on his knees in a vain attempt to escape while pleading his innocence and warning the men that 'God is watching'.

Seconds later a fighter to the left of the camera fires his automatic weapon several times, with the bullets striking the child in the head and killing him instantly. The camera then closes in on the dead child's face and shows brain and 

US officials say Iraq did not ask the US to provide air support for the Tikrit offensive, even though the US-led military coalition has been conducting air strikes in much of Iraq since August and has deployed hundreds of US soldiers to try to regenerate an Iraqi army that collapsed last June.

General Dempsey said Iran and its proxies have been operating inside Iraq since 2004, but the Tikrit campaign signals a new level of involvement.

He said that about two-thirds of the force seeking to retake Tikrit is comprised of Iranian-based Shia militia fighters.

Iraqi government troops make up the other third. Tikrit, the hometown of former Iraqi president Saddam Hussein, is a predominantly Sunni city.

Retaking the ISIS stronghold is considered vital if government forces are to succeed in their plan to force ISIS out of the oil rich city of Mosul, the terror group's Iraqi power base which lies just 140 miles north of Tikrit on Highway 1 - a road that effectively marks the front line in northern Iraq.

(dailymail.co.uk)