Christians in the Middle East are being "attacked and massacred" and driven into exile, the leader of the world's Anglicans said Wednesday in his first Christmas sermon.

Justin Welby used his first Christmas Day address as Archbishop of Canterbury to remember those suffering for their faith in the cradle of Christianity.

"Today, singing of Bethlehem, we see injustices in Palestine and Israel, where land is taken or rockets are fired, and the innocent suffer," he told the congregation at Canterbury Cathedral in southeast England.

"We see injustice in the ever more seriously threatened Christian communities of the Middle East.

"They are attacked and massacred, driven into exile from a region in which their presence has always been essential.

"We see terrible news in South Sudan, where political ambitions have led towards ethnic conflict," he said.

Welby, the spiritual head of the Church of England, is the leader of the world's 80 million Anglicans. He was enthroned in Canterbury in March and visited Jerusalem in June.

Earlier on Christmas Day, a car bomb targeted a Baghdad church as worshippers left after mass, killing at least 14 people.

Iraq has seen its Christian population plunge in the years of bloody sectarian killings and other violence that followed the 2003 US-led invasion of the country.

Meanwhile Archbishop of Westminster Vincent Nichols, the Roman Catholic leader in England and Wales, struck a similar chord in his midnight mass at Westminster Cathedral in London.

"Christians are the most widely persecuted religious group in the world today and this evening we think especially of the Middle East, especially of Egypt, Iraq and Syria," he said.

"As Prince Charles said last week: 'Christianity was literally born in the Middle East and we must not forget our Middle Eastern brothers and sisters'."

"We come to this Cathedral this evening freely and relatively easily, ready to give a simple act of witness to our faith. But for many going to church is an act of life-risking bravery. We thank them and seek to be inspired by their courageous faith."