By Jason Benham
JUBA, Sudan (Reuters) - Millions of jubilant south Sudanese started voting on Sunday in a long-awaited independence referendum that is expected to see their war-ravaged region emerge as a new nation.
Huge queues built up outside polling stations before dawn in the southern capital Juba where banners described the week-long ballot as a "Last March to Freedom" after decades of civil war and perceived repression by north Sudan.
"I am voting for separation," said Nhial Wier, a veteran of the north-south civil war that led up to the vote. "This day marks the end of my struggles. In the army I was fighting for freedom. I was fighting for separation."
The referendum was promised in a 2005 peace deal that ended Africa's longest civil war, fueled by oil and ethnicity, between the mostly Muslim north and the south, where most people follow Christianity and traditional beliefs.
In the north, the prospect of losing a quarter of the country's land mass -- and the source of most of its oil -- has been greeted with resignation and some resentment.
Sudanese president Omar Hassan al-Bashir, who campaigned for unity in the run-up to the vote, has been making increasingly conciliatory comments and this month promised to join independence celebrations, if that was the outcome.
U.S. President Barack Obama on Saturday said a peaceful, orderly referendum could help put Sudan back on a path toward normal relations with the United States after years of sanctions but warned a chaotic vote will mean more isolation.
Southern president Salva Kiir urged long lines of voters to be patient after casting his ballot at 8 a.m. (0500 GMT).
"I believe Doctor John (Garang) and all those who died with him are with us today and I want to assure them they have not died in vain," he said, referring to the southern rebel leader who died in a helicopter crash months after signing the accord.
Juba and Khartoum already looked liked the capitals of two different countries on Sunday.
In Juba, actor George Clooney and U.S. Senator John Kerry mingled with dancing and singing crowds. Voters waiting outside one polling station burst into a rendition of the hymn "This is the day that the Lord has made."
"It is something to see people actually voting for their freedom. That's not something you see often in your life," Clooney told Reuters.
In Khartoum voting centres were empty, and southern districts were quiet -- tens of thousands of exiled southerners have returned for the vote. There were no banners acknowledging the historic referendum.
ALL VOTE MATERIALS DELIVERED
The vote's organising commission told Reuters it had defied gloomy forecasts of delays to deliver all voting materials on time for Sunday's deadline.
The logistical achievements have not been matched by political progress. Southerners went to the polls without knowing the exact position of their border with the north or how much of Sudan's debt they will have to shoulder after a split.
The two sides have been locked in negotiations for months over how they might share out oil revenues -- the lifeblood of both their economies -- and settle other issues after secession. There is no public sign of progress.
The south also will have to face up to its own internal ethnic rivalries and resolve a bitter dispute with the north over the ownership of the central Abyei region, where there were reports of clashes involving Arab nomads on Friday and Saturday.
Still, north and south proceeded to the referendum while drawing a line under more than half a century of fighting.
"The risk is always there. There is always lots of tinder about and there are a lot of unresolved issues, including Abyei," said Derek Plumbly, chairman of the Assessment and Evaluation Commission that monitors the north-south peace deal.
"But neither side really wants to go back to war. I believe they will find their way through."
(Additional reporting by Jeremy Clarke in Juba, Andrew Heavens and Opheera McDoom in Khartoum; writing by Andrew Heavens; editing by Myra MacDonald)