The graphic footage was allegedly shot by affiliates of ISIS’ so-called Khorasan province, and begins with dozens of jihadi fighters marching through scrubland, clutching Kalashnikovs to their chests and waving ISIS banners.

The commander of the group appears in the video to welcome the allegiance of the Islamic Movement of Uzbekistand (IMU), which announced its loyalty to the group last month.

Moments later, the executioner’s sword is pictured being sharpened against a spinning stone wheel before a close-up shot shows the sword being removed from its holster.

The prisoner, clad in the now infamous orange jumpsuit of the condemned, gives a short speech to the camera before the execution.

The condemned man, claimed by the group to be a member of the Afghan security forces, appears on his knees in front of a row of jihadi fighters before cutting to black as the executioner swings his sword.

The video was released just hours after Prime Minister David Cameron announced that the RAF had killed three ISIS militants in Syria, among them two Britons.

One of the militants killed, 21-year-old Reyaad Khan, from Cardiff, had bragged of plotting ‘murder on our streets’ before his death.

The Cardiff-born fighter was revealed by Mr Cameron as the target of the drone strike, in the ISIS capital of Raqqa.

Mr Cameron insisted in his announcement that there was ‘no other means to stop him’.

It is the first time that a British attack has been launched in a foreign country outside of a war and sparked claims the families of the dead fanatics could now sue the government.

Although the group has claimed a member of the Afghan security forces was beheaded, according to news portal Khaama.com, the identity of the executed man has not yet been verified, nor have the charges on which he was executed.

The Islamic Movement of Uzbekistan, which is listed as a terrorist organisation by the U.S., released a video last month which allegedly shows the IMU’s leader Usmon Ghazi and his fighters taking an oath of allegiance to ISIS and its leader Abu Bakr al-Baghdadi. 

Uzbekistan is located in central Asia and was once part of the former Soviet Union. Islamic terrorists have been linked to sporadic violence in the country for more than a decade. 

(dailymail.co.uk)