JUBA South Sudan has told the United Nations it will pull all police out of a disputed region on its border with Sudan and is committed to halting all fighting with its northern neighbor, but Khartoum declared a state of emergency in some border areas.
The conflicting developments on Sunday raised questions whether United Nations and African Union appeals for an end to more than three weeks of border clashes between Sudan and South Sudan would bear fruit and avert full-blown war in the oil-producing region.
South Sudan, which gained independence from Sudan nine months ago under a 2005 settlement, told the United Nations it planned to withdraw all police from the Abyei region, according to a letter from Juba's mission to the world body.
The letter, dated April 28 and seen by Reuters on Sunday, also said South Sudan was committed to an "immediate cessation of all hostilities" - after the African Union ordered both parties to stop fighting. The pan-African body has given the rivals a three-month ultimatum to hammer out a deal.
The decision to withdraw from Abyei was taken at a cabinet meeting chaired by southern President Salva Kiir on Saturday.
"All of these acts of peace are being done to reaffirm and demonstrate with concrete measures my government's true commitment to finding a peaceful solution to the outstanding matters with the Republic of Sudan," said the letter.
But in Khartoum, Sudanese President Omar Hassan al-Bashir declared a state of emergency in some areas of South Kordofan, White Nile and Sinnar provinces bordering South Sudan, the state-linked Sudanese Media Center (SMC) said on its website. It gave no further details.
The areas have witnessed clashes recently between the Sudanese army and the SPLM-north, a militia group that wants to topple Sudanese President Omar Hassan al-Bashir and whom Khartoum accuses Juba of supporting.
Khartoum and Juba accuse each other of supporting rebel militia in each other's territories. Both denies the other's charges.
The South's army (SPLA) said on Sunday 21 people had died in two days of clashes with Khartoum-backed rebels in the South's oil-producing Upper Nile state. The SPLA said it was also pursuing Khartoum-backed militia near Western Bahr al-Ghazal.
Weeks of border fighting along the 1,800 km (1,100) mile contested border escalated after the two failed to agree on a string of disputes after the south's separation. The impasse has already halted nearly all oil production in both countries, damaging their shaky economies.
South Sudan's army seized the contested Heglig oilfield earlier this month but announced a withdrawal more than a week ago, bowing to U.N. pressure.
The South has since accused Khartoum of launching air strikes against its territories, a claim Sudan denies.
For the first time on Sunday, Sudan defended its right to use air strikes against South Sudanese troops who Khartoum says are inside Sudanese territory.
Sudan's ambassador to the United Nations, Dafallah ElHaj Ali Osman, however, stopped short of saying whether Sudan had carried out the air strikes over the past few weeks. The U.N. Security Council has demanded that Sudan stop the air attacks.
The United Nations has urged Sudan and South Sudan to withdraw troops and police from Abyei, a border region of fertile grazing land, which both countries claim.
South Sudan seceded from Sudan in July, six months after a referendum agreed under a 2005 peace deal that ended years of civil war which killed more than 2 million people. A similar vote was originally planned for Abyei, but was never held as both sides have not been able to agree on who can participate.
There are 3,800 U.N. peacekeepers in Abyei after the Security Council authorized the deployment in June last year.
On Saturday, Sudan said it had arrested a Briton, a Norwegian and a South African, accusing them of illegally entering Heglig to spy for its adversary South Sudan.
South Sudanese officials denied the allegations and said the men were working with the United Nations and aid groups clearing mines and had got lost in the remote territory.
Sudan said on Sunday it was looking into their arrest.
"They are still under investigation," said El-Obeid Morawah, a foreign ministry spokesman, without elaborating.
Norwegian People's Aid identified one of those arrested as John Sorbo, 50, describing him as one of the group's "most experienced workers" who has spent more than seven years in South Sudan working on mine clearance.
Sorbo had been on a five-day mission in South Sudan's Unity state, the aid group said in a statement on its website.
(Additional reporting by Ulf Laessing in Khartoum; Writing by Mark Heinrich and Yara Bayoumy; Editing by Andrew Heavens)