The Archbishop of Sydney, Dr Glenn Davies, has joined calls for prayer and international assistance for Iraqi Christians facing severe persecution, even death, for their faith.

"It is an outrage that a community established in the early centuries of the Christian era should face expulsion from their own land, simply for their faith." Dr Davies said in a public statement.

In Mosul, near the ruins of the ancient city of Nineveh, the militant Islamic group ISIS gave Christians an ultimatum: convert to Islam, pay a "protection tax" or face death. 

Churches have been looted, burned or occupied. Christian homes have been marked with the Arabic letter "N" (for the word 'Nasrani' which translates to 'Nazarene', a follower of Jesus). This has been followed by a social media movement among Christians in the west to try to highlight the persecution.

Thousands of Christian families have been driven from the city.

"In the same area where God sent the prophet Jonah to turn back the people of Nineveh from their evil ways, we pray for a turning back of the evil which has come upon the Christians of Mosul, stripped of their livelihood, property and possessions."

"The Australian government, the international community and the UN must not stand by while such persecution continues unabated." Dr Davies said.

The Archbishop called on churches to pray for peace and justice in Iraq and also for Palestinian Christians caught in the conflict on the West Bank and the Gaza.

"We have entered a period of significant suffering for Christians around the world: from Iraq to Syria and from Egypt to Sudan." the Archbishop said. "While the Cross is the symbol of suffering for all who are followers of Jesus of Nazareth, we have a responsibility to stand with our brothers and sisters in the face of such unmitigated persecution."

Photo: Iraqi homes daubed with the 'Nasrani' symbol