CAIRO- The Islamic State group has released a video purportedly showing the beheading of Egyptian Coptic Christians the jihadists say they captured in Libya.
Egypt’s President Abdel Fattah al-Sisi immediately called an urgent meeting of the country’s top security body and declared seven days of mourning.
Al-Azhar, the prestigious Cairo-based seat of Islamic learning, denounced the “barbaric” killings.
The footage released by IS online shows handcuffed hostages wearing orange jumpsuits being beheaded by their black-suited captors in a coastal area the group said was in the Libyan province of Tripoli.
In the latest issue of the IS online magazine Dabiq, the group said 21 Egyptian hostages were being held in Libya, and in Sunday’s video, shot from several angles, the beheadings of at least 10 hostages were seen.
Egyptian state television also broadcast some of the footage from the IS video.
The security body that will meet in Cairo groups Sisi, his defence and interior ministers and top military figures.
Egypt last year denied reports of having carried out air strikes on Islamists in Libya.
In a statement, Al-Azhar said it had heard the news of the beheadings “of a group of innocent Egyptians with great sorrow and grief”.
The latest IS video comes just days after the jihadists released footage showing the gruesome burning alive of a Jordanian pilot the group captured after his F-16 came down in Syria in December.
The highly choreographed video showing the killing of Maaz al-Kassasbeh triggered global outrage.
Sunday’s video, entitled “A message signed with blood to the nation of the cross”, has a scrolling caption in the first few seconds referring to the hostages as “People of the cross, followers of the hostile Egyptian Church”.
One of the masked captors, wearing a military uniform and pointing a knife to the camera said in English: “Today we are in the south of Rome, in the land of Islam Libya… the sea you have hidden Sheikh Osama bin Laden’s body in, we swear to Allah we will mix it with your blood.”
Al-Qaeda founder Bin Laden was shot and killed in a dramatic helicopter raid by US special forces in Pakistan in the early hours of May 2, 2011 and later buried at sea in an unidentified location.
After the beheadings shown on Sunday, a scrolling caption on the footage said: “The filthy blood is just some of what awaits you, in revenge for Camilia and her sisters.”
A background voice believed to be IS spokesman Abu Mohamed al-Adnani says: “We swear to Allah we will take revenge, even if it takes a while.”
Egyptian women Camilia Shehata and Wafa Constantine were the wives of Coptic priests whose alleged conversion sparked a sectarian dispute in Egypt in 2010.