Sudan on Saturday denied launching an air strike against South Sudan during fragile peace talks, saying it had only targeted Darfuri rebels inside northern territory.

"What happened is the Justice and Equality Movement (JEM) rebels tried to attack Sudan by coming through South Sudanese territory and SAF (Sudanese Armed Forces) responded to them, but inside Sudan," the official SUNA news agency quoted one of Khartoum's negotiators to the African Union-led talks as saying.

"SAF didn't violate South Sudanese territory," said the negotiator, Omar Dahab.

South Sudan's military spokesman Philip Aguer told AFP that Sudan, on Friday morning, had bombed South Sudan's northern Bahr el Ghazal state, wounding two civilians.

He added that "this might have implications because maybe that is the intention of Sudan to bomb us and to stop talking."

But the Sudanese negotiator Dahab said his team "is ready to continue direct negotiations with South Sudan's delegation."

Sudan's President Omar al-Bashir and his South Sudanese counterpart Salva Kiir on July 15 held their first private talks since the two countries came to the brink of all-out war in April, prompting the United Nations to order a ceasefire and a resumption of AU-led talks in Ethiopia.

The resolution gave the two sides until August 2 to settle critical issues, including a dispute over oil, unresolved after the South's separation in July last year.

Khartoum accuses South Sudan of backing a major insurgency in South Kordofan state, as well as in Blue Nile, and also of working with the JEM rebels.

The South says it does not back the rebels but suspected JEM fighters were seen alongside its troops during the border fighting in April. JEM denied involvement.

South Sudan accuses the north of backing insurgents in the South as well.

The UN resolution calls on both sides to halt the practice.

Earlier in July at the AU-led talks in Addis Ababa, Sudan and South Sudan agreed to a cessation of hostilities and a commitment to pursue peace, though fell short of signing a concrete deal.

Since border tensions escalated in late March, repeated claims of fighting have coincided with attempts to negotiate.