BEIRUT (AFP) - The ISIS terror group threatened Britain in an Internet video Sunday showing the killing of five "spies" which also shows a little boy vowing to "kill kuffar" (non-believers).
The SITE Intelligence Group said the video shows five men from Raqa, capital of the self-declared extremist "caliphate" straddling Syria and Iraq, confessing to carrying out acts of espionage then being slaughtered one by one in graphic footage.
The video, posted to YouTube, then ends with a boy with a British accent, who appears to be only about five-years-old, and dressed in military fatigues and a black bandanna bearing the white mark of ISIS (Islamic State in Iraq and Syria) says: "We will kill kuffar [NON BELIEVERS]over there."
Following that an English-speaking ISIS fighter who hides his face under a black mask mocks British Prime Minister David Cameron for challenging ISIS, and calls him an "imbecile".
The "confessions" of the five do not clearly identify which countries they worked with, but one mentions the international coalition led by the United States battling against ISIS .
The video said they passed videos or photos of the living conditions in Raqa to people in Turkey, or monitored the movements of ISIS fighters.
The following sequence shows the five wearing orange jumpsuits and kneeling before five masked fighters, all in military fatigues and armed with pistols.
"This is a message to David Cameron," says one of the gunmen. "How strange it is that we find ourselves today hearing an insignificant leader like you challenge the might of ISIS."
British warplanes, which were already attacking ISIS positions in Iraq, at the beginning of December began targeting the exremists in Syria also.
"Only an imbecile would dare to wage war against a land where the law of Allah reigns supreme and where the people live under the justice and security of sharia" or Islamic law, the fighter says.
"We will continue to wage terror... and one day invade your land, where we will rule by the sharia." He said those who want to continue fighting "under the banner of Cameron" should ask themselves: "Do you really think your government will care about you when you come into our hands, or will they abandon you as they have abandoned these spies and those who came before them?"
Each of the five men is then killed with a bullet to the head.
ISIS often releases propaganda videos when it suffers setbacks on the battlefield, experts say.
In Iraq last Sunday, federal forces declared victory in the battle for Ramadi, which IS seized in May 2015.
And on Dec 26, an alliance of Kurdish and Arab fighters in northern Syria seized the strategic Tishreen Dam from ISIS which the terror group had held since 2014.