International observers have endorsed the conduct of southern Sudan's independence referendum and have predicted that a vote for secession is "virtually certain."
A group of observers led by former U.S. President Jimmy Carter said Monday the vote was "consistent with international standards for democratic elections," and that based on reports from vote counting centers the outcome spells independence for the south.
U.S. Secretary of State Hillary Clinton also approved of the way the referendum was conducted. In a written statement, she praised leaders in both the north and the south for creating conditions under which voters could cast ballots "freely and without fear."
The voting, which spanned several days last week, was called for in a 2005 peace agreement between Sudan's mostly Christian and animist south and the mainly Muslim north. That accord ended decades of civil war.
Final results of the poll are not expected before mid-February. And if the outcome is as predicted, a new nation will be born in July.
In another development, Sudanese security forces have arrested an Islamist opposition leader. Hassan al-Turabi's arrest Monday came just hours after he predicted that northern Sudan is facing a popular uprising in the face of increasing economic problems that he says will be worsened by the expected secession of the oil-rich south.
Turabi was a key ally of Sudanese President Omar al-Bashir. But a falling out 10 years ago landed him in prison. He was released from jail under the 2005 accord.
Voting in the southern Sudan referendum was largely peaceful, although there have been tribal clashes along the north-south boundary in the oil-rich Abyei region that left 46 people dead.
Control of the disputed Abyei region is one of several issues the north and south must resolve.
Some information for this report was provided by AFP and Reuters.