In the 11-minute film released by the Al-Hayat Media Center, the Islamic State's media wing, an unidentified masked militant threatens attacks on the United Kingdom, specifically sending a "message" to British Prime Minister David Cameron.
"Oh slave of the White House, oh mule of the Jews. How strange it is that we find ourselves today hearing an insignificant leader like you challenge the might of the Islamic State," says the masked man, looking into the camera and speaking British English with a Middle Eastern accent. "How strange it is that the 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 Islamic State."
"It seems that you, just like your predecessors Blair and Brown, are just as arrogant and foolish," he continues. "In fact, David, you are more of an imbecile. 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 the Sharia.
"Only an imbecile would dare to anger a people who love death the way that you love your life. Oh British Government. Oh people of Britain. Know that today your citizenship are under our feet. And that the Islamic State, our country, is here to stay. And we will continue to wage jihad, break borders and one day invade your land where we will rule by the sharia."
The hostages are dressed in orange jumpsuits. All appear to be Middle Easterners. Some say in the video that they are from Raqqa, Syria; Another said he is from Benghazi, Libya. None said they were from the U.K.
The video shows the masked militant standing behind the five kneeling hostages before he and four other masked men, all dressed in army fatigues, execute the five. The video has not been independently verified.
At the end of the video, a young boy dressed in military attire is also seen. He warns in English: "We are going to go kill the kafir [non-believers] over there."
The latest video seems to imitate execution videos previously released featuring Mohammed Emwazi, the British Islamic State militant known as "Jihadi John." Emwazi was reportedly killed by a U.S. airstrike in Raqqa in November.
Charlie Winter, a senior researcher in transcultural conflict at Georgia State University in Atlanta told The Guardian that the Islamic State -- also known as Daesh, ISIS and ISIL -- has launched a propaganda campaign in an attempt to distract from mounting losses, particularly after losing control of the Iraqi city of Ramadi.
"Among other things, ISIS is trying to seize the initiative again, having taken a major hit with the loss of Ramadi," Winter said, adding there had been "an uptick in propaganda videos and photo essays" recently, designed to "divert attention away from big tactical blows like Ramadi.