ADDIS ABABA - Peace talks between Sudan and South Sudan are said to be yielding slow progress despite reports of fresh clashes on the ground and questions about Sudan's withdrawal from the disputed Abyei region.  Tensions were high as the latest round of negotiations opened with a South Sudanese demand for sanctions against Khartoum.

The second day of African Union-mediated talks Wednesday began three hours late.  Diplomats said negotiating teams were scrambling to organize their positions.

South Sudan's chief negotiator Pagan Amum told reporters the initial discussions are limited to basic procedural issues. "We will be presenting the steps we are required to take, and they are required to take, and the steps jointly we are required to take," he explained. "This will be presented in a matrix for agreement and then agreeing on a timeline for when to implement them, with the aim of respecting the timelines as indicated in the Road Map and the Security Council resolution."

A previous round of talks broke down last month as fighting raged along the disputed border.  The chief AU mediator, former South African president Thabo Mbeki, said at the time the neighbors had descended into a state of war.

Fears of a return to war prompted the U.N. Security Council this month to approve resolution 2046.  The resolution orders the feuding neighbors to stop fighting, withdraw forces from the disputed and oil-producing Abyei region, and return to the negotiating table.

South Sudan pulled its last 700 police officers out of Abyei by last Tuesday's deadline.  As the current round of talks got underway, the United Nations certified that Khartoum had pulled its troops out, too.   But well-informed diplomatic sources say an unspecified number of Sudanese police remain in Abyei.

South Sudan's Pagan Amum says Khartoum should be hit with U.N. sanctions for multiple violations of the Security Council resolution.

"The government of Sudan did not withdraw from Abyei within the two weeks as required.  This is a violation," Amum stated. "We also asked the representative of United Nations to report this violation, and this non-compliance by the republic of Sudan, and we expect Sudan to suffer sanctions and measures from the Security Council as promised."

Despite the strong words, Amum described this week's meetings as "good" and said he is ready to continue.

Khartoum's delegation has declined to speak to reporters since the talks began.  Instead they issued a statement stressing their commitment to reach a negotiated settlement on all issues, and promising "full adherence to peace and stability."

South Sudan broke way from Khartoum last July after decades of conflict, leaving unsettled a series of bitter disputes over borders, citizenship and sharing of oil revenues.

Oil is the backbone of both countries' economies, and both have suffered since South Sudan shut down production in January, accusing Sudan of stealing oil that traveled through northern pipelines.  Sudanese authorities said the oil was taken in lieu of payment of fees it was owed by the south.