Syria, London - what has the feel of a desperate propaganda video, a child speaking with a British accent points out where the executions will take place.
He says: “We will kill the the kuffar [non believers] over there."
The terror group’s five helpless victims, dressed in orange jump suits and wearing handcuffs, are filmed as they speak to the camera in Arabic.
However the video seen by Express.co.uk does not show the actual execution.
The video comes a few weeks after Mr Cameron won a crucial Commons vote to allow the bombing campaign against ISIS, also known as Daesh, to be extended from Iraq into Syria.
It was reported on Christmas day that a British unmanned Reaper drone had taken out a number of ISIS extremists.
With five shackled prisoners kneeling in front of him, the masked gunman speaking in a British accent then taunts David Cameron.
He describes the Prime Minister as an "imbecile" before apparently shooting the hostages, who were accused of spying for the British security services.
The executioner was filmed saying: “Your children will pay for your deeds.
He goes on: “How strange it is that we find ourselves today hearing an insignificant leader like you.”
"How strange it is that a leader of a small island, threatens us with a handful of planes.
"One would have thought, you would have learned the lessons of your pathetic master in Washington, and his failed campaign against the IS.
"But it seems that you, just like your predecessors Blair and Brown are just as arrogant and foolish. In fact, David, you are more of an imbecile.
"Only an imbecile would dare to anger a people who love death the way that you love your life."
The video, which was thought to have been filmed in the desert in the self-declared ISIS stronghold of Raqqa, has not yet been independently verfied.
A Foreign Office spokesman said: "We are aware of the video and are studying its contents."
Shock waves were sent through Britain last year when horrifying videos of the gruesome murders of David Haines and Alan Henning were posted online by ISIS.
Mr Haines, 44, from Perth in Scotland, was captured by the evil terror group in March 2013 while working for a French charity in Syria.
While Mr Henning, 47, of Salford, was taken hostage while delivering food and supplies on an aid convoy to refugees in Syria in December 2013.
The videos of their separate horrific murders were met by shock and disgust from British public figures across the nation.
ISIS was also behind the executions of American journalists James Foley and Steven Sotloff, American aid worker Peter Kassig and Japanese journalist Kenji Goto.
The latest propaganda from the twisted jihadis comes just months after footage was released appearing to show caged prisoners being lowered into a swimming pool to drown.
But since then, Daesh have been left with almost nowhere to run after the world ramped up air strikes against the twisted jihadis in Syria.
Russia claims to have wiped out hundreds of terrorists and their weaponry in just a matter of months.
While last month saw the despicable terrorists lose one of their key areas in Iraq, Ramadi, after Iraqi forces took back the city as part of a US-coalition plan.
Britain joined the call to end the twisted terror group back in November after it extended RAF airstrikes from Iraq into Syria.
Posterboy Jihadi John is noticeably absent in the latest video, just months after he was reportedly killed in a US airstrike.
source: daily express