Hundreds of southern Sudanese headed south from the capital Khartoum on Thursday ahead of a key referendum over whether the south will secede from Africa's largest country.
Men, women and children crammed into buses piled high with luggage that left from a staging area 20 miles south of Khartoum in the latest large scale return of southern refugees from the north.
"We have over 87,000 already registered and now more people are moving in earnest to register," said Abdullah Kam, an official from the south's Unity province which is overseeing this particular return. "Today 90 buses and 38 trucks left Khartoum, bringing the number returning so far (to Unity province) to 32,000."
Southerners fought a two decade civil war against the Muslim, northern-dominated central government in which 2 million people died and more than a million headed north to escape the fighting.
The war only ended with a 2005 peace treaty that stipulated the south would be allowed to vote in January on whether they would remain part of Sudan.
While there will be polling for the referendum in the north, many southerners fear their vote might be interfered with in the Muslim heartland of the country. Most southerners are Christian or animist.
"Yes, some people are happy to return to their home area and we expect more people to register for return," said Kam.
Most of the returnees to Unity province come from the Nuer tribes, with a few from the Dinka, one of the south's dominant tribal groups.
The total number of southerners who immigrated to the north is unknown, though the government estimates some 2 million lived in Khartoum alone during the war.
The southern government challenges these figures but has yet to present any numbers of its own.
The southern government is worried that the north won't allow it secede because many of the country's oil wells are located in the south.
Southern authorities have announced they will use trains, trucks and buses to bring their people home and families would be sheltered at special reception centers in each town until the referendum. The government says it has asked for international assistance to cope with the returnees.
Preparations for the referendum are running behind schedule, and officials have warned that little time remains to complete critical tasks.