New York – The UN leader Ban Ki-moon on Monday condemned cross-border air raids by Sudan on rival South Sudan, and called on the countries' leaders to stop their "slide" to war.
The two countries have engaged in sporadic fighting along their common oil-rich border in recent months, prompting international concerns about the possibility of all-out war.
Ban's call for calm came after Sudan's President Omar al-Bashir ruled out any future talks with rival South leader Salva Kiir, who was in Beijing to drum up support from China, a traditional ally of Khartoum.
"The secretary-general condemns the aerial bombardment on South Sudan by Sudanese armed forces and calls on the government of Sudan to cease all hostilities immediately," said deputy UN spokesperson Eduardo del Buey.
Ban "reiterates that there can be no military solution to the disputes between Sudan and South Sudan. He calls on President Bashir and President Kiir to stop the slide toward further confrontation and urges both sides to return to dialogue as a matter of urgency," the spokesperson added.
South Sudan said Sunday that it had completed a withdrawal of its forces from the disputed oil town of Heglig. But air raids were staged on Monday on Bentiu, the capital of the South's Unity state.
Bashir, making a visit to Heglig, said the time for talks with Kiir's government, which he has previously described as an "insect" that must be eliminated, was over.
"No negotiation with those people," Bashir told soldiers in Heglig, which the South occupied for 10 days. "Our talks with them were with guns and bullets."
Large plumes of grey smoke
On Friday, Bashir and Defence Minister Abdelrahim Mohammed Hussein - both wanted by the International Criminal Court for alleged war crimes in Sudan's Darfur region - declared the army had forced Southern soldiers out of Heglig.
Kamal Marouf, a Sudanese army commander, claimed in Heglig on Monday that more than 1 000 South Sudan troops were killed in the clashes.
But Kiir had already announced that his forces would leave under "an orderly withdrawal" from Heglig, in response to appeals from world leaders and to allow a resumption of dialogue.
Unity Governor Taban Deng said Sudanese bombs nonetheless fell on a key bridge and a market, killing at least two children in Bentiu.
"We have been pressured by the international community to pull out of Heglig and this is the consequence - we have brought the war to home," Deng said.
In the market, stalls were on fire and large plumes of grey smoke rose high into the air, as screaming civilians ran in panic.
Sudan denied the attack but the United States condemned it and urged an "immediate" halt to hostilities and a return to talks.
France's foreign affairs spokesperson Bernard Valero denounced the "aggression" as unacceptable, warning it ran the risk of worsening the situation.
The presidents of Sudan and South Sudan "must have the courage to negotiate" because their people deserve peace, US President Barack Obama said.
Mac Paul, the South's deputy director of military intelligence, called the attack "a clear provocation."
The air raid is the latest of several along the disputed border.
The violence in Heglig was the worst since South Sudan won independence in July after a 1983-2005 civil war in which an estimated two million people died.
In Beijing, Kiir was expected to plead his case to Chinese authorities, but analysts said China was unlikely to take sides and would keep pushing for dialogue.
China has been a key ally and the largest economic partner of diplomatically isolated Sudan, but it is keen not to alienate the South, the world's newest nation and source of most of the former Sudan's oil.