PM: IS Killing Video Is 'Desperate Stuff'
Downing Street says a new Islamic State video of a masked man and young boy shows the terror group is "under pressure".
Security and intelligence officials are examining the 10-minute film which purports to show the masked militant with a British accent threatening the UK and calling David Cameron an "imbecile".
The recording, which has not been independently verified, contains footage of five men of Middle Eastern appearance wearing orange jumpsuits - who IS said were British spies - being shot dead.
A child aged about five, who apparently spoke with a UK accent, also appears in the video wearing an IS headband and a camouflage outfit.
But Mr Cameron called the video "desperate stuff" from a group that is "losing territory" and "increasingly losing anybody's sympathy".
Authorities are working to identify the masked man, who is also pictured wearing combat fatigues and is heard describing the UK Prime Minister as a "slave of the White House".
The man said: "One would have thought you would have learnt the lessons from your pathetic master in Washington and his failed campaign against Islamic State.
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"But it seems that you, like your predecessors Blair and Brown, are just as arrogant and foolish.
"In fact David you are more of an imbecile."
He added: "You will lose this war as you lost in Iraq and Afghanistan."
In the 10-minute film, the five detainees apparently confessed to the allegations that IS accused them of.
The Prime Minister's spokesman dismissed the video as a "propaganda tool".
He said: "It serves as a reminder of the barbarity of Daesh and what the world faces with these terrorists. It's also clear it is propaganda and should be treated as such."
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Sky's Enda Brady said: "The prisoners are obviously speaking under extraordinary duress.
"They apparently confess to the crime of spying for the UK government."
In a statement, the Foreign Office said: "We are aware of the video and are examining its content."
The RAF has carried out at least 10 airstrikes against Islamic State in Syria since MPs backed the use of military force early in December.
UK warplanes have also been bombing IS targets in Iraq for a number of months.
The video emerged days after Mr Cameron promised to crack down on IS sympathisers, stressing in a New Year's message that all Britons should have "loyalty" to their country.
The footage also came in the wake of recent losses by IS, including in the Iraqi city of Ramadi which the army claimed to have captured from the militants.
The jihadist group has lost 40% of areas it once controlled in Iraq, according to US President Barack Obama.
And it has also lost a large amount of territory in Syria to Kurdish fighters.
Last November, British IS militant Mohammed Emwazi, known as "Jihadi John", who appeared in a number of beheading videos, was believed to have been killed in a drone strike in Syria .
A number of other UK jihadists have also been targeted and killed or are being hunted by authorities.
