Voters in Southern Sudan began celebrating after the end of a week long referendum. The poll is widely expected to divide Africa's largest country. Officials and observers noted high turnout and praised the peaceful voting process but they also expect waves of political disputes between the north and the south.

After decades of civil war, people in Southern Sudan have made their choice on whether to become the world's newest country.

But peace is far from certain, as many challenges lie ahead.

Many outstanding issues remain, including drawing the future border and deciding who will control the oil-rich area of Abyei, the Blue Nile and south Kordofan areas.

With nomadic herders common throughout the country, deciding who falls under which nationality will be a daunting task for either government.

Experts do not expect the two parties to complete the border demarcation during the transition period which is six months.

Problems drawing an agreeable border between north and south Sudan are hampered by the vast distance and geography that separates Africa's largest country.

Experts say the two parties have to reach an agreement that guarantees citizens' rights without any discrimination regarding region or ethnicity.

Meanwhile, Sudan's external debts constitute a heavy burden for a fragile economic system in the north and another one yet to be built from scratch in the south.

Sudan's debts have amounted to over 30 billion U.S. dollars, most of which date back 30 years. Economists stressed the importance for north and south Sudan to exert joint efforts to have all or most of the debts be exempted.

Another thorny issue will be settling the conflict in the Darfur region, which has suffered a stalemate since the Sudanese government withdrew its negotiating delegation from the Doha talks in December last year.

The international community has urged Darfur rebel groups to participate in the Doha negotiations to reach a lasting peace agreement.