( CNN ) -- Five people were killed and five others wounded after an airplane dropped bombs Saturday on a town in South Sudan , a military spokesman in that fledgling country said -- though a Sudanese military spokesman denied any such attack . Col. Philip Aguer , a spokesman for the Sudan People 's Liberation Army of South Sudan , said that the aerial strike hit a market area in Rubkona , which is part of Unity state , at 1 p.m. Saturday ( 6 a.m . ET ) . Abiemnom County in that state , as well as two counties in Warrap state , were also attacked Saturday , Aguer said . But Al-Sawarmi Khalid , a spokesman for the Sudanese Armed Forces , said , `` We have not carried out attacks into South Sudan . '' Both military spokesmen referenced Heglig , a key oil installation in South Kordofan state that produces nearly half of Sudan 's oil and was seized by South Sudan 's military this week . Aguer insisted Heglig is part of South Sudan . Meanwhile , Khalid said that Sudanese military forces were `` approaching Heglig from all sides . '' Sudan 's ambassador to the United Nations welcomed a U.N. Security Council statement this week demanding `` a complete , immediate and unconditional end to all fighting and a withdrawal of the SPLA from Heglig and an end to aerial bombardments . '' `` We will observe closely the behavior and attitude of the reaction of the government of the South to this call and if they do n't heed it , we will reserve our right to exercise the right of self-defense and we will chase them out , `` Ambassador Daffa-Alla Elhag Ali Osman said . The European Union 's foreign policy chief , Catherine Ashton , has called South Sudan 's move to occupy Heglig `` completely unacceptable '' and urged forces to withdraw immediately . The African Union similarly has called on forces to pull out and for aerial bombardments to stop . Yet South Sudan 's ambassador to the United Nations blamed the Khartoum government for attacks on their forces at the border , which she said provoked their actions at Heglig . `` South Sudan had no choice . It had to defend itself to deter attacks on South Sudanese territory , '' Agnes Oswaha said . `` South Sudan is prepared to withdraw troops as long as a mechanism is put in place that the area can not be used to launch further attacks . '' South Sudan gained independence from the north in July , the result of a referendum overwhelmingly approved by voters last year . The referendum was part of a 2005 peace deal that ended decades of civil war between the two sides that killed about 2 million people . Despite the split , several outstanding issues have yet to be negotiated , including citizenship , border demarcations and oil revenue sharing . When they separated , South Sudan acquired three-quarters of Sudan 's oil reserves . The two countries have been locked in negotiations over how much the landlocked South Sudan should pay to use a pipeline and processing facilities in the north . In late July , South Sudan halted oil production after accusing Sudan of `` stealing '' $ 815 million worth of its crude . Sudan said it confiscated the oil to make up for unpaid fees .
An airplane drops bombs on a market in Unity state , a South Sudanese spokesman says . A Sudanese spokesman says its military did n't carry out any attacks in South Sudan . A dispute continues regarding Heglig , a key oil installation that South Sudan recently took over . South Sudan is at odds with Sudan on border issues , months after becoming independent .