Southern Sudanese officials appealed for international help Sunday after northern Sudanese troops seized a disputed border town, and the U.N. Security Council and secretary-general demanded an immediate end to military action and withdrawal.
But they stopped short of promising specific action to dislodge northern soldiers from a flash point that threatens to re-ignite the country's civil war.
Northern tanks rolled into the town of Abyei Saturday night, scattering southern troops that were there as part of a joint security unit. The U.N. compound was also hit with mortar fire, and Secretary-General Ban Ki-moon said two U.N. peacekeepers were wounded.
The seizure of Abyei followed an attack on a convoy of northern soldiers by southern forces on Thursday and two days of aerial bombardment of the area by the north.
Doctors Without Borders said in a statement that its hospital in Agok, 40 kilometers (24 miles) south of Abyei, received 42 wounded people late Friday and early Saturday. It said that by Sunday morning nearly the entire population of Abyei had fled and the town was almost empty.
The escalation in violence comes less than two months before South Sudan, which is predominantly ethnic African, is due to become the world's newest country on July 9 after voting overwhelmingly to secede from the Arab-dominated north. The north and south fought a civil war for more than two decades before a 2005 peace deal offered the south the chance for independence.
Under the peace deal, Abyei was also due to have a referendum to decide whether it would remain part of the north or south, but it was canceled amid disagreements over who was eligible to vote.
"The present occupation (by the northern government) is illegal, this is the responsibility of the (U.N.) Security Council to see that they are withdrawn," said Barnaba Marial Benjamin, the south's information minister.
The northern army accused the south of violating the peace agreement and said the northern occupation of the area, including Abyei town, would continue until an accord could be reached that would guarantee security and stability in the region.
President Omar al-Bashir's northern ruling party said in a statement the northern armed forces were "entrusted with protecting Sudan's territory and stability and the security of its citizens in the south and north."
Both north and south claim Abyei, a fertile region near several large oil fields, and its disputed status has long been recognized as a potential trigger for violence. Hollywood actor George Clooney set up a project to monitor the area by satellite, fearing a confrontation between the two sides could draw Sudan back into the civil war that killed 2 million of its citizens.
The U.N. Security Council, which is visiting Sudan, released a statement Sunday blaming both sides for the violence. It said the south had attacked the convoy of northern soldiers and the north had escalated the confrontation by occupying Abyei.
The council demanded "the immediate withdrawal of all military elements from Abyei" and called on both sides to restore calm, uphold the 2005 peace agreement, "and recommit to a negotiated political settlement on the future status of the Abyei area."
Ban, the U.N. chief, echoed the call for an immediate halt to military operations and urged both sides to "desist from further acts of antagonism" and uphold their previous commitments to maintain peace and security in the Abyei area, a statement from his spokesman said.
The secretary-general also called on leaders from the north and south to "engage in serious discussions to find a final settlement to the Abyei issue before July 9," the statement said.
Activist John Prendergast called for the international community to take tough action against northern Sudan, which he said regularly has broken international agreements.
"Instead of more carrots from the international community it's time for real consequences," he said. "The U.S. should work with the U.N. Security Council to suspend the normalization process, freeze talks on debt relief, and impose target sanctions on the ringleader of this across-the-board escalation, presidential adviser Nafie Ali Nafie and others associated with this violence."
Southern army spokesman Col. Philip Aguer said the occupation of Abyei was an act of war by the north but that for now the south would not respond. Southern Sudan is no match for the north on the battlefield.
A Western diplomat interviewed by The Associated Press said countries would condemn the violence but it was unclear if they would take stronger measures because they did not have much leverage. He asked for anonymity because of the sensitivity of the situation.
Al-Bashir, the northern president, is already subject to a travel ban and is wanted by the International Criminal Court on charges of genocide and crimes against humanity for violence in the western Sudanese region of Darfur.
President Barack Obama's envoy to Sudan said the occupation of Abyei was a "disproportionate" response by the north to hostilities that flared Thursday and could hurt U.S. relations with the Sudanese government.
"It inhibits the ability of the entire international community to move forward on a number of issues critical to the future of Sudan," said Ambassador Princeton Lyman.
But northern Sudan remained defiant Sunday, canceling planned meetings with U.N. officials, the Western diplomat said. The northern defense minister said the south has been "provoking" his troops.
"There is no way but to respond in kind," Gen. Abdul Rahim Hussein told the daily newspaper Al-Akhbar in an interview published Sunday.
The escalation follows an agreement by the two sides to withdraw all "unauthorized forces" from the area. But like many previous U.N.-brokered deals on Abyei this year, it was not fully implemented.
Benjamin, the southern information minister, said the north was an increasingly "unreliable partner." It was unclear how the occupation of Abyei would affect talks between the two sides on outstanding issues like citizenship for those living on the wrong side of the border.
The south is mainly animist and Christian and its people are linguistically and ethnically linked to sub-Saharan Africa. The north is overwhelmingly Muslim and many members of the government consider themselves Arabs. Most of Sudan's oil is in the south but the pipeline needed to export it runs through northern territory to a northern-held port.
Associated Press writers Mohamed Osman in Khartoum, Sudan, and Edith M. Lederer at the United Nations contributed to this report. Houreld contributed reporting from Nairobi, Kenya.