KHARTOUM - South Sudan accused Sudan on Friday of attacking its military positions in an oil region, imperiling the chances of a promised ceasefire between the neighbours, but Khartoum denied the charge.
The 1,800 km-long (1,200 mile) border between the two countries had been largely quiet for the past 48 hours, raising hopes they could begin talks to end a series of clashes over oil exports, border demarcation and citizenship that have pushed them closer towards a full-blown war.
South Sudan's army (SPLA) spokesman Philip Aguer said Khartoum was again on the offensive on Friday: "Today they hit our positions with ground artillery in Teshween, Lalop and Panakuach."
Aguer said Sudanese warplanes had also bombed Lalop in South Sudan's Unity state on Thursday and an SPLA position had been shelled in Teshween.
Sudan's army spokesman denied the charge.
"None of this is true. On the ground there are other enemies, like opposition (groups) to the South Sudanese," Sudanese army spokesman al-Sawarmi Khalid said.
U.S. Secretary of State Hillary Clinton called on Sudan on Friday to stop all cross-border attacks, "particularly its provocative aerial bombardments".
Reports of the attacks came after Sudan said it was ready to accede to international demands for a halt to hostilities, albeit with a significant caveat.
"The ministry points out, in light of the repeated attacks and aggressions that South Sudan's army is carrying out, ... the Sudanese armed forces will find itself forced to use the right to self defence," the foreign ministry said on Thursday.
Limited access to the remote border areas makes it difficult to verify often contradictory statements from both sides.
THREAT OF SANCTIONS
The U.N. Security Council on Wednesday passed a resolution threatening Sudan and South Sudan with sanctions unless they stopped fighting and resumed talks within two weeks, endorsing an African Union deadline of May 8 for negotiations to begin.
Sudan's ruling National Congress Party (NCP) has shrugged off the threat, saying such U.S.-backed resolutions "aim to punish Sudan and reward the aggressor", the state SUNA news agency said on Friday.
Sudanese President Omar Hassan al-Bashir, in power since 1989, had at first ruled out negotiations with his southern "enemy". Sudan later said it was willing to talk about "security issues", as both neighbours accuse each other of backing rebel militias. Both deny the charges.
"This is not someone who wants to negotiate. The security problems with north and south have to be addressed first. How could you go for negotiations when someone's armed forces is still in our territory," Mahdi Ibrahim, a leading official from Sudan's NCP, told reporters in Nairobi.
"Let the issues of security be addressed before we hold negotiations on oil and other issues," Ibrahim added.
The African Union has drawn up a seven-point road map for peace that demands both countries withdraw their troops from contested areas and resume talks.