Exchanged accusations have recently escalated between Sudan and South Sudan of violating fragile agreement of ceasefire, at a time when the African Union was seeking to bring the two sides back to the table of negotiations, hosted by Ethiopia.

South Sudan delegation to the Addis Ababa negotiations on Friday announced suspension of direct negotiation with Sudan at the Ethiopian city of Bahar Dar due to what it said bombardment by Sudan's army of areas inside South Sudan, but Sudan denied those claims and accused South Sudan of supporting Darfur rebel groups.

Atif Kiir, spokesman of South Sudan delegation said, "the negotiations were suspended in protest against Sudanese army's bombardment of area in North Bahral-Ghazal State."

However, Sudan denied South Sudan government's accusations that Khartoum's army had bombarded areas inside South Sudan.

"These accusations are absolutely untrue. We have not conducted any bombardment south of the international borders," Al-Sawarmy Khalid Saad, spokesman of Sudanese Armed Forces (SAF), told Xinhua on Saturday.

"These accusations have political dimensions. The south may want to stop the negotiations currently going on in Ethiopia," he added.

He said the Sudanese army was ready to cooperate with monitoring committees formed by the African Union (AU) to verify such allegations, saying "there are monitoring and complaint committees and we are ready to cooperate with them."

Sudanese political analysts believe that suspension of the direct negotiations marked the beginning of the collapse of the current round of negotiations, led by Thabo Mbeki, Chairman of the African Union High-Level Implementation Panel on Sudan (AUHIP).

"It was not easy to persuade the two sides to engage in direct negotiations and therefore suspension of the direct negotiations means returning to the zero point," Mussa Awad, a Sudanese political analyst, told Xinhua.

"The recent events at Heglig have caused a lack of confidence between the two sides; therefore it was not easy to bring the two sides back to the negotiation table. South Sudan's decision to suspend the direct negotiations could be the beginning for the collapse of this round."

He further accused South Sudan of attempting to foil the current round of negotiations, saying "Juba had worked to foil the previous round via its adherence to a new map including strategic Sudanese areas, and presently it is trying to hamper the negotiations through escalation of accusations against Khartoum."

The Ethiopian resort of Bahar Dar has been hosting the most recent round of negotiations between Sudan and South Sudan, under the mediation of the African Union.

Many previous rounds of talks have failed to resolve the outstanding issues between the two countries including security, oil sharing and border demarcations files in addition to the affiliation of the disputed oil-rich area of Abyei.