The Bishop of Kadugli is calling upon Christians worldwide to pray and fast ahead of South Sudan's secession next month.
Bishop Andudu Adam Elnail has warned of a possible "genocide" in the Nuba Mountains region, where violence has broken out in recent weeks.
The region, home to many Christians, will remain under the control of Khartoum and the Muslim North when South Sudan gains its independence on July 9.
As Sudanese tanks and artillery move in, hundreds of thousands of Nuba are fleeing their homes and development agencies have withdrawn their staff.
UN officials and eyewitnesses escaping the bloodshed tell of elders being executed by the Sudanese Army and bombing campaigns that have destroyed churches and homes.
With Khartoum ordering the UN peacekeeping mission out, there are serious concerns that atrocities will spiral unchecked across the state of South Kordofan.
"Once again we are facing the nightmare of genocide of our people in a final attempt to erase our culture and society from the face of the earth," said Bishop Elnail.
"It is not a war between armies that is being fought in our land, but the utter destruction of our way of life and our history, as demonstrated by the genocide of our neighbours and relatives in Darfur.
"This is a war of domination and eradication, at its core it is a war of terror by the government of Sudan against their people."
He expressed concern for the future of Christians in the North, which President Omar al-Bashir declared will be ruled by Sharia law after July 9.
The bishop said that President al-Bashir's refusal to recognise the legitimate presence of the Christian minority in the North was a "declaration of their determination to also end the remembrance of our Christian heritage that dates back two thousand years".
The bishop is asking that Christians in Sudan and around the world join in praying and fasting for the country on June 26.
"Please pray and fast with us as you are able for a solution to this crisis," he said.
Bishop fears genocide in Sudan
Published 22 June 2011 | Karen Peake