“This morning the (Sudanese) air force came and bombed… areas in Unity state,” South Sudan’s President Salva Kiir said, according to a BBC report.
He added: “After this intensive bombardment our forces…. were attacked by the (Sudan Armed Forces) and militia.
“It is a war that has been imposed on us again, but it is (Sudan) who are looking for it.”
A spokesperson for South Sudan’s armed forces, the SPLA, was quoted elsewhere as saying: “After repulsing the attack, the SPLA pursued the withdrawing SAF (Sudanese Armed Forces) force and they captured two bases of SAF between Heglig and Teshwin.
“This is a self-defence measure by SPLA to defend itself against aggressors.”
On Monday several border regions witnessed assaults with each accusing the other of instigating attacks.
Sudan’s President Omar Bashir was due to fly to the South Sudanese capital of Juba for a summit on 3 April, but has now called off this meeting following the clashes.
The neighbours remain at loggerheads over numerous issues since the South won independence last year. The most pressing is the issue of how to split oil revenues. The South took with it about three quarters of the enlarged area’s total oil production but is currently reliant on Sudan’s infrastructure to export its oil.
South Sudan earlier this year shut in its production after accusing Sudan of stealing its oil. The South has also penned agreements with neighbours to build pipelines to the Indian Ocean to circumvent use of Sudan’s infrastructure.