* Fighting in central Abyei blocks north-south route
* Civil war that ended in 2005 sent southerners north
* Southerners struggle to find jobs, want to go home
By Ulf Laessing
WAD AL-BASHIR CAMP, Sudan, May 24 (Reuters) - Southerners' furniture and belongings are piled high in this slum in Sudan's northern capital, ready to catch the next truck home before the region breaks away to form a new nation in July.
But the route is blocked. Fighting in the disputed central region of Abyei has threatened to plunge north and south back into conflict. The luggage is left baking under the searing sun.
"We have all packed up but cannot go because we heard the roads are closed," said a man in his 30s, trying to escape the scorching heat with fellow southerners under a tent next to piles of desks, bed frames and mattresses in Wad al-Bashir camp.
War brought many of the southerners to Khartoum. They sought work or refuge during two decades of conflict between north and south that ended with a peace deal in 2005. It was followed by a vote this year, when southerners voted to secede.
Some are leaving because they can no longer find jobs. For others, even those who spent much of their lives in Khartoum, the mainly Muslim north is no longer home for southerners who are mostly Christians or follow traditional beliefs.
"I don't have a job. I work here and there as labourer but I cannot live like that with my family," said Manot, 38, a Christian who has been here with his family since 1983.
"In the south it's better because you can go and work in the fields and farms," he said, waiting like others to return.
"We don't know when we can go. We want to leave because we don't have jobs here," said another man, sitting in the tent.
The violence in Abyei -- claimed by north and south and supposed to hold its own referendum on which to join -- has added to the uncertainty. The northern army seized control of the oil-producing region at the weekend, forcing thousands to flee.
Tanks moved into the main town in the area sandwiched between north and south, and a U.N. mission says the town has been looted and burned.
"The events in Abyei are going to have a big impact," said Claire Bolt, a project development and coordination officer at the International Organisation for Migration (IOM) in Khartoum.
Around 300,000 southerners have gone home from the north of Sudan since October by train, Nile barge or road, according to estimates by the IOM which is advising both governments.
There are no reliable figures for the number of southerners still in the north. But the IOM estimates some 25,000 have been stranded on the way at railway stations and other places.
One man in the camp said some families had been waiting six months as roads had been closed or were too unsafe to use. Finding places on trains or barges was not always possible or was simply too costly.
"The roads are not safe and it's expensive to go. We hope for help from the United Nations," said another southerner in the group sitting under the tent.
The slum consisting of houses made of wood or corrugated iron just outside Khartoum has been home to tens of thousands of southerners since the 1980s when fighting between north and south was at its peak.
Some southerners feel they will no longer be welcome in the north after secession. The north is mainly Muslim, while most southerners follow Christian or traditional beliefs.
Sudanese President Omar Hassan al-Bashir said in December, before the vote, that the north would adopt an Islamic constitution if the south opted for independence.
"We can go to church here but in the south we can live better. We can find jobs on farms and in the fields," said Majang, another southerner. "Life is tough here."
But life in the south will not be easy. Decades of war left the region ravaged and underdeveloped with few roads or other infrastructure. Violence in the south, since the independence vote in January, has left at least 1,100 dead.
Those challenges will keep some southerners in the north.
"For social, economic and educational reasons, many southern Sudanese who live in Khartoum have an interest in maintaining links with the north," said Aly Verjee, senior researcher of the Rift Valley Institute.
"For all the drawbacks, Khartoum does present opportunities not available throughout South Sudan," he said.
But in Wad al-Bashir camp, many want to leave regardless.
"We want to go. How can you live here without jobs?" said a Christian called John, sitting under the shade of a makeshift tent. (Additional reporting by Khaled Abdelaziz; editing by Edmund Blair and Tim Pearce)