Why Are Egypt's Christians Being Targeted?

Egypt's Copts are the largest Christian community in the Middle East and are estimated to account for around 15% of the country's population.

"Coptic" is used to describe the native Christians living in the country, where Christianity is a large minority religion.

The Coptic Orthodox Church was founded in the first century by Saint Mark the apostle, who wrote the second Gospel of the New Testament.

The church carefully preserves the Orthodox Christian faith and follows the apostles' doctrines.

A video released on Sunday apparently shows 21 Copts being beheaded by Islamic State-inspired combatants.

The footage, which is 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".

It makes reference to Egyptian women Camilia Shehata and Wafa Constantine, the wives of Coptic priests whose alleged conversion to Islam caused a sectarian dispute in Egypt five years ago.

Shehata went missing for five days in July 2010 following a domestic argument. Police later found her and escorted her home.

Coptic Christians staged protests when she disappeared, but when Shehata was returned, Islamists took to the streets claiming she had chosen to convert to Islam and was being held by the church against her will.

Wafa Constantine went missing in 2004, reportedly after her husband refused to grant her a divorce.

As reports of her conversion to Islam spread, she was temporarily sequestered at a convent.

After the hostages are beheaded in the video, a scrolling caption reads: "The filthy blood is just some of what awaits you, in revenge for Camilia and her sisters."

Bishop Angaelos, general bishop of the Coptic Orthodox Church in the UK, said the killings had caused "deep feelings of sorrow and pain".

"While it may seem illogical or incomprehensible, we also pray for those who have carried out these horrific crimes, that the value of God's creation and human life may become more evident to them, and in this realisation, that the wider effects of pain brought by this and other acts of brutality may be realised and avoided.

"We pray for an end to the dehumanisation of captives who become mere commodities to be bartered, traded and negotiated with."