Trying to broker any kind of peace will be difficult. The conflict is complicated by accusations of some of the groups being armed by the Khartoum government. Meanwhile, some factions of the tribes have disarmed while others took the opportunity to gather more weapons, suggesting a lack of cohesive leadership.
From this IRIN article that we found at Reuters Alertnet, we find some background about the armed conflict in Sudan.
On 12 June, fighting broke out close to Nasir in Upper Nile State, Southern Sudan, when hundreds of armed Jikany Nuer men attacked a flotilla of 31 boats, including 27 carrying grain and other supplies for the UN World Food Programme (WFP), according to UN officials and eyewitnesses.
"The boats were carrying supplies to our enemy," said Jikany youth Peter Gatwech, recovering from a bullet wound to his stomach in Nasir hospital.
Dozens of people in Nasir said the attack on the boats was prompted after three other boats - thought to be carrying ammunition or arms upstream to the Lou - joined the convoy.
The attack cut supplies to the more than 19,000 displaced Lou Nuer people in the eastern town of Akobo, who had fled earlier fighting against the Murele.
The river convoy had to pass through Nasir - home of the Jikany Nuer people - and the latter want revenge for an attack by Lou gunmen on 8 May that left 71 mainly women and children dead in the village of Torkech.
"They killed so many of us," said Thiyang Gatbel, a young Jikany girl shot in the arm during the night attack, and still recovering in hospital. "We were sleeping outside under mosquito nets, and they surrounded the village."
In May, the special representative of the UN Secretary-General and head of the UN Mission in Sudan (UNMIS), Ashraf Qazi, warned that death rates in the south had outnumbered those in the war-torn western region of Darfur.
CPA needs bolstering
Southern Sudan and the north must bolster efforts to implement the 2005 Comprehensive Peace Agreement (CPA) to ease tensions in the south and avoid possible conflict with the north, observers have warned.
"If this agreement fails, there is a risk that all of Sudan will go to war again," said Melanie Teff of Refugees International. "Every possible step must be taken to prevent a return to the horrors of the past."
The CPA ended 22 years of conflict between north and south, and led to the establishment of a semi-autonomous administration in Southern Sudan.
"The danger of violence across Southern Sudan could intensify in the months ahead," the New York-based Human Rights Watch (HRW) said in a 21 June report. It warned of the "failure of the government of Southern Sudan and the UN Mission in Sudan (UNMIS) to protect civilians".