(CNN)  -- Census-takers are fanning out across Sudan this week in a landmark headcount meant to determine how to divide power and wealth in the war-weary African nation.



A south Sudanese soldier keeps watch, with the threat of civil war still high in the war-torn country.



The census is a key component of a 2005 peace agreement that ended a 22-year civil war which killed 2 million people and displaced an estimated 4 million others. The war pitted a government dominated by Arab Muslims in northern Sudan against black Christians and animists in the south.



Delays in starting the census were among the reasons cited when southerners withdrew last year from a government of national unity. They rejoined the government two months later, but tension and occasional fighting near the disputed territory of Abyei has threatened to reignite the civil war.



"God forbid, that's a distinct possibility," said Andebrhan Giorgis, senior policy adviser for Africa for the International Crisis Group, a non-profit organization that seeks to prevent and resolve crisis. "It's quite worrisome."



North-south tensions have worsened even as international attention has focused more on persistent violence in the Darfur region of western Sudan, where roughly 300,000 people have been killed since 2003 in a campaign of killing, rape and displacement that the U.S. calls genocide.



Results from the national census, which began Tuesday, will be used to establish electoral districts and determine political representation in a national assembly, Giorgis said.



"It's an important milestone," he told CNN on Wednesday.



The  U.N. peacekeeping mission in Sudan also hailed the census as vital, in a statement Tuesday.



The census is key to establishing voting districts in advance of national elections scheduled for 2009. It is also critical in determining how oil wealth is to be shared between the north and south, who have a history of animosity and mistrust.



It's unclear how census-takers will operate in Darfur - and how accurately they will be able to count the population there, Giorgis said. E-mail to a friend
where North-south tensions continue? where Count will be used to determine? what did the country have?
Darfur region of western Sudan, the population there, a history of animosity and mistrust.
question: where North-south tensions continue?, answer: Darfur region of western Sudan, | question: where Count will be used to determine?, answer: the population there, | question: what did the country have?, answer: a history of animosity and mistrust.