The Archbishop of Sydney, Dr Glenn Davies, says Australians should be shocked, repulsed and outraged by the slaughter of 21 Egyptian Coptic Christians, murdered for their faith in Libya.

The men, originally from Egypt, had travelled to Libya to find work.

Amid instability in the region, they were kidnapped by a group linked to IS, led to a beach and beheaded.

A propaganda video was circulated to news outlets, which has caused outrage in the Middle East. (See above: A shot from the start of the terrorist's video)

There have since been air strikes by Egyptian and Libyan air force jets on  Derna, an eastern coastal city thought to be the base for local supporters of the Islamic State.

"The filming of this evil and barbaric act was another attempt by the so-called Islamic State to strike fear into the hearts of Christians and others throughout the region." the Archbishop said. 

"The victims were singled out as 'people of the cross' and died for their allegiance to Jesus as martyrs have done through the centuries."

"We pray for the Coptic Church to stand firm as it suffers such persecution. To our brothers and sisters in the Anglican Church in Egypt and throughout the Middle East, our hearts and prayers are with you."

"For those bent on evil and violence, we pray God would turn their hearts to seek mercy at the feet of Jesus."

Dr Davies supported calls from the Primate of the Middle East, Presiding Bishop Mouneer Anis, for prayer that the international community would respond wisely to the attacks in the region. 

The Archbishop also backed calls for diplomatic action by Australia and for special consideration to be given to the inclusion of Coptic Christians from North Africa in any humanitarian intake.