Residents of the flashpoint Abyei region claimed by both Sudan and South Sudan voted on the third and final day Tuesday in an unofficial referendum to decide which country they belong to.
The vote, which is organised by only one of the two peoples who count Abyei as home, is not recognised by either Khartoum or Juba, and has been criticised by the African Union as a "threat to peace".
However, Luka Biong, spokesman for the Abyei Referendum High Committee, insisted the poll had seen a strong turnout from the 65,000 registered voters, and that the ballot had been conducted peacefully.
"It has been smooth with few problems, people have come out peacefully and voted to decide freely their own future," Biong told AFP.
The fate of Abyei is one of the most important and sensitive issues left unresolved since South Sudan became an independent state in 2011, ending two decades of civil war in Sudan.
AU chief Nkosazana Dlamini-Zuma said the vote was illegal and its organisers were risking sparking a return to war between civil war foes in Juba and Khartoum.
"They pose a threat to peace in the Abyei area, and have the potential to trigger an unprecedented escalation on the ground... with far-reaching consequences for the region as a whole," she said in a statement on Monday.
Patrolled by some 4,000 Ethiopian-led UN peacekeepers, the area is home to the settled Ngok Dinka tribe, closely connected to South Sudan, as well the semi-nomadic Arab Misseriya, who traditionally move back and forth from Sudan grazing their cattle.
Only the Ngok Dinka are voting in the referendum -- although organisers insist it is open to all -- and the Misseriya have already angrily said they will not recognise the results of any unilateral poll.
"We begin counting the votes on Wednesday," Biong added, who comes from the Ngok Dinka people and was a former senior official in South Sudan.
Abyei was meant to vote on whether to be part of Sudan or South Sudan in January 2011 -- the same day Juba voted overwhelmingly to split from the north -- as part of the 2005 peace deal which ended Sudan's two-decade long civil war.
That referendum was repeatedly stalled, and Sudanese troops stormed the Lebanon-sized enclave in May 2011 forcing over 100,000 to flee southwards, leaving a year later after international pressure.