South Sudan accuses Sudan of bombing village - USA TODAY

Military spokesman Col. Philip Aguer said Sudanese Antonov planes bombed the village of Rumaker in Northern Bahr el Ghazal state near the two countries' border early Friday morning. Aguer said two civilians were slightly injured.

The Sudanese government in Khartoum, however, promptly rejected the accusation, saying its aircraft only attacked the Darfur rebel Justice and Equality Movement within its own borders.

Sudan's SUNA state news agency quoted government spokesman Omar Dahab as saying that Khartoum had warned Juba that the rebel forces were in South Sudan planning operations against Sudan and that the government would strike them if they "infiltrated" the country.

Sudan made several bombing runs into South Sudan earlier in the year, bringing the two nations to the brink of war in April, but Friday's attack is the first bombing reported by South Sudan since early May.

"We didn't expect anything like this," said Aguer. "It is a surprise."

Sudan and South Sudan are engaged in negotiations in Ethiopia over a host of issues, including the separation of their once-unified oil industry and the demarcation of the long, joint border.

South Sudan peacefully broke away from Sudan last year after an independence vote, but the two sides never resolved the most contentious issues between them. A bloody civil war between them that lasted more than two decades had ended only in 2005.

In January, South Sudan shut down its oil production after accusing Khartoum of stealing oil shipped through Sudanese pipelines for export. Sudan said it had taken the oil in lieu of transit payments for the use of its pipelines. The decision has cost both governments millions of dollars in revenue, further burdening their weak economies.

In April the two sides clashed openly along the north-south border over the disputed oil-rich town of Heglig. It has been controlled by Sudan since the split and is responsible for around half of Sudan's oil production. But South Sudan claimed it was part of the south and captured it in April. After widespread condemnation, South Sudan said it pulled out. Sudan says its military forced the southern troops out.

Following the clashes, the United Nations Security Council issued a resolution in May, calling on the two sides to resume negotiations immediately. They have been in Ethiopia for talks since the resolution, but South Sudan's Information Minister Barnaba Marial Benjamin said the recent bombing "is not in the spirit of dialogue."

The U.N. Security Council resolution includes an Aug. 2 deadline for the two sides to reach a resolution on all outstanding issues. According to the resolution, the Security Council will consider imposing sanctions if the two sides do not reach a deal.

This is not the first time South Sudan has accused Khartoum of cross-border bombings during negotiations, which have been taking place on and off for more than a year.

"Maybe certain extremists do not want the talks," said Marial. "Why would they continue bombing?"

Khartoum' Dahab said, however, that the Sudanese government is ready to continue direct peace and oil negotiations with South Sudan.