Residents of the remote and disputed Abyei border region said they would press ahead with their own referendum next week on whether to join Sudan or South Sudan, despite warnings it could trigger violence in the volatile area.
The ownership of Abyei was left undecided when South Sudan declared independence from Sudan in 2011 - and a long-promised official plebiscite on its status has been stalled by arguments over who is entitled to vote.
Leaders from the overwhelmingly pro-South Sudan Dinka Ngok group said they were tired of waiting for the poll over the territory that has small oil reserves and has seen several clashes between Sudanese and South Sudanese troops.
"We have come to the conclusion that the best way to do it, we organise our own referendum and we go on and tell the world what we want," said Acuil Akol, from the committee organising the vote.
Around 100,000 Dinka Ngok in other parts of the South had come home to take part in the three-day vote, officials said in Abyei town, where buildings still bore the scars of fighting.
Relying solely on community donations, the organisers started registering voters on Sunday and plan to have 29 stations ready for polling from 27 October.
A unilateral Dinka Ngok poll would have no legal weight, they acknowledged, especially as both Sudan and South Sudan have said they will not recognise the result.
But its almost certain decision to join South Sudan would antagonise heavily armed, pro-Sudan Misseriya nomads, who drive their livestock through Abyei for large parts of the year and have demanded the right to vote over its future.
"Abyei continues to be a source of conflict between the two countries and things could escalate if all the parties involved don't come to an agreement," said Zachariah Akol, director of the Juba-based Sudd Institute.
"Khartoum could use ... militia in order to disrupt whatever is happening," said Luka Biong, a fellow at Harvard Kennedy School and an adviser to the referendum organisers. It could put the government of South Sudan in a bad situation."
South Sudan seceded under the terms of a peace deal that ended decades of north-south civil war. Fighting erupted between the sides in 2008 and, in the month's running up to the South's departure, Khartoum sent tanks into Abyei town, forcing thousands to flee.
In the town, many of the buildings are still without roofs, with crumbling walls. UN peacekeepers mount daily patrols through the unpaved streets.
Abyei was a major battleground in the years of north-south civil war and has emotional, symbolic and strategic significance for both sides.
"We don't want to listen to anybody this time. We are the people of Abyei and we decide to do what we want ... We want the world to know that we are going for the referendum," said Asha Abbas Akuei, another member of the organising committee who represents Abyei in South Sudan's parliament.
Abyei is one of a series of disputes festering between Sudan and South Sudan, among them other border areas and oil rights.
Sudan's President Omar Hassan al-Bashir is to visit the south's capital Juba on Tuesday, the Sudanese state news agency SUNA reported, a visit portrayed as the latest attempt to mend ties.
Abyei will be near the top of their agenda, said South Sudan Foreign Affairs spokesperson Mawien Makol Arik, adding: "There is no reason to have a vote at this time."