A video showing the mass beheading of Coptic Christian hostages has been released by militants in Libya affiliated with the Islamic State group.
The killings raise the possibility that the Islamic militant group, which controls about a third of Syria and Iraq in a self-declared caliphate, has established a direct affiliate less than 500 miles from the southern tip of Italy.
One of the militants in the video makes direct reference to that possibility, saying the group now plans to "conquer Rome."
The militants had been holding 21 Egyptian Coptic Christians hostage for weeks, all labourers rounded up from the city of Sirte in December and January. It was not clear from the video whether all 21 hostages were killed.
It was one of the first such beheading videos from an Islamic State group affiliate to come from outside the group's core territory in Syria and Iraq.
The Egyptian government and the Coptic Church, which is based in Egypt, both declared it authentic.
The Coptic Church in a statement called on its followers to have "confidence that their great nation won't rest without retribution for the evil criminals."
The video's makers identify themselves as the Tripoli Province of the Islamic State group. A still photo, apparently taken from the video, was published last week in the Islamic State group's Dabiq online magazine, indicating a direct connection between the Libyan militants and the main group.
The video, released last night, depicts several men in orange jumpsuits being led along a beach, each accompanied by a masked militant. The men are made to kneel and one militant, dressed differently that the others, addresses the camera in North American-accented English.
"All crusaders: safety for you will be only wishes, especially if you are fighting us all together. Therefore we will fight you all together," he said.
"The sea you have hidden Sheikh Osama Bin Laden's body in, we swear to Allah we will mix it with your blood."
The men are then laid face-down and simultaneously beheaded.
The militant speaker then pointed northward across red-stained waves and said, "We will conquer Rome, by Allah's permission.
