Islamic State kills 21 Egyptian Christians

An image grab taken from a video released by the jihadist media arm Al-Hayat Media Centre on February 15, 2015 purportedly shows black-clad Islamic State (IS) group fighters leading handcuffed hostages, said to be Egyptian Coptic Christians, wearing orange jumpsuits before their alleged decapitation on a seashore in the Libyan capital of Tripoli.

Islamic State released a video purporting to show the beheading of a group of Egyptian Christians kidnapped in Libya, violence likely to deepen Cairo's concerns over security threats from militants thriving in the neighbouring country's chaos.

Egypt's state news agency MENA quoted the spokesman for the Coptic Church as confirming that 21 Egyptian Christians believed to be held by Islamic State were dead.

In the video, militants in black marched the captives, dressed in orange jump suits, to a beach the group said was near Tripoli. They were forced down onto their knees, then beheaded.

The video appeared on the Twitter feed of a website that supports Islamic State, which has seized parts of Iraq and Syria and has also beheaded Western hostages.

A caption on the five-minute video read: "The people of the cross, followers of the hostile Egyptian church."

Thousands of Egyptians have travelled to Libya in search of jobs since an uprising at home in 2011, despite advice from their government not to go to a country sliding into lawlessness.

Before the killings, one of the militants stood with a knife in his hand and said: "Safety for you crusaders is something you can only wish for."

President Abdel Fattah al-Sisi called a seven-day mourning period and an urgent meeting of Egypt's top military commanders, state television reported.

The Coptic Church said it was confident the Cairo government would seek justice. Al Azhar, the centre of Islamic learning in Egypt, said no religion would accept such "barbaric" acts.

The families of the kidnapped workers had urged Cairo to help secure their release. In the southerly Minya Governorate, relatives screamed and fainted upon hearing news of the deaths.