CAIRO, Feb 15 (Aswat Masriya) - A video showing the beheadings of the Egyptians kidnapped in Libya was released on Sunday night on social media. 

The video starts with images of the kidnapped Egyptian Copts being led by men clad in black, except for one, along the shore of Tripoli, according to video subtitles.

The masked men are believed to be part of a Libyan division of Islamic States fighters in Iraq and Syria. 

The video is titled, "a message signed with blood to the nation of the cross." 

The speaker in the video, who is also masked, is dressed in army fatigues and narrates in English a message, saying, "O crusaders, safety for you will be only wishes, especially when you are fighting us all together. Therefore, we will fight you all together."

The speaker said this last line while pointing his dagger to the camera.   

The speaker said "we swear to Allah" to mix the sea where "Sheikh Usama Bin Laden was hidden" with "your blood."

After the speaker delivers the message, the abductees who were kneeling are forced to lie down and their throats are slit simultaneously.

Egyptian President Abdel Fattah al-Sisi declared a week of mourning and called for an urgent meeting of the National Defence Council.   

After the beheadings, the speaker says the killings "were in revenge for Camilia and her sisters."

Camilia Shehata is an Egyptian woman who was at the centre of controversy back in 2010 after her disappearance following news that she converted from Christianity to Islam. A group of Egypt's conservative Muslims believe that she was eventually forced back into Christianity. 

The video footage is consistent with images that had been released on social media on Thursday, showing the kidnapped Egyptians in orange jumpsuits with the sea in the backdrop.

Twenty-one Coptic Egyptians were abducted in the Libyan city of Sirte on two separate occasions in December and January, only one week apart.