( CNN ) -- Major conflict could return to southern parts of Sudan unless international action bolsters a faltering peace accord , ten aid agencies said in a report released Thursday . A resumption of conflict between north and south in Sudan , meanwhile , would make a sustainable peace impossible in Darfur , a region of western Sudan that has been the scene of what the U.S. calls genocide , the aid groups said . `` It is not yet too late to avert disaster , but the next 12 months are a crossroads for Africa 's largest country , `` said Maya Mailer , policy advisor for Oxfam International and the report 's co-author . The warnings were underscored by news Thursday of a clash that killed scores in Southern Sudan , the latest instance of tribal violence among southerners that has alarmed the United Nations . Locals said fierce fighting in Warap State , one of the most remote regions of the south , killed 140 people , wounded 90 , and led to the theft of tens of thousands of cattle early this month or in late December , the United Nations said . `` The human toll is massive -- hundreds if not thousands displaced . The death toll is massive , '' said Lisa Grande , a top U.N. humanitarian official in Southern Sudan . `` These attacks are a matter of great concern . '' Resurgent tribal violence in the south also concerned the 10 aid groups . They released their report , `` Rescuing the Peace in Southern Sudan , '' two days before the fifth anniversary of a 2005 peace deal that ended a grinding war between the Sudanese government and southern rebels in the Sudan People 's Liberation Movement . They said that peace deal is `` on the brink of collapse . '' That war pitted a northern government of Arab Muslims against southern blacks who follow Christianity and traditional African religions . It killed 2 million people and forced several million others from their homes . The peace deal conferred limited autonomy on southern Sudan and ended one of Africa 's longest and deadliest wars even as a separate conflict that erupted in 2003 raged in Darfur , killing roughly 200,000 , the United Nations says . Despite the peace deal , violence in the south increased last year , Mailer said , and it could escalate further to become one of the biggest emergencies in Africa this year . About 2,500 people were killed and 350,000 fled their homes in southern Sudan last year , the aid agencies said . Many died in tribal violence between southerners . Outside countries have ignored the problem and have not provided sufficient help , the agencies said . The United Nations says more people have been killed in southern Sudan in 2009 than in Darfur , where a separate conflict drew international attention , prompted charges of genocide and led the International Criminal Court to indict the Sudanese president , Omar Hassan al-Bashir , for war crimes . Some southerners blame their former enemies in the north for instigating violence in the south . As the south plans to participate in national elections in April , many southerners say the north has hindered access to registration materials , logistical support and voter education , the United Nations said . The north denies those charges , but they 're among the reasons that analysts worry about an outbreak of north-south violence in a region already buckling under the weight of corruption , cattle rustling and revenge attacks . Sudan needs diplomatic involvement from neighboring countries and the international community to help secure the 2005 peace agreement , said Paul Valentin , international director of Christian Aid , one of the agencies that produced the report . `` A return to war is by no means inevitable , but it depends whether the world heeds the warning signs of the past year and has the political will to save the peace , '' Valentin added . Other agencies that produced the report include the International Rescue Committee , Save the Children and World Vision . The report urges the U.N. Security Council to ensure that protecting civilians becomes a core priority for a peacekeeping force in Sudan . The agencies also called on the international community to mediate between the northern and southern parties before the national elections -- the country 's first multi-party elections in 24 years -- and before a referendum on independence , which is scheduled for early next year . Southern Sudan is roughly the size of Texas but has only 30 miles of paved roads and few health facilities . It is so underdeveloped that the U.N. says a 15-year-old girl in the south is more likely to die in childbirth than finish school . `` After five years of peace , southern Sudan remains one of the poorest regions on earth . People hoped the peace would bring economic benefits and development , but this has happened far too slowly and in some areas not at all , '' said Francisco Roque , country director of Save the Children in South Sudan . `` We are very worried about children who seem to be increasingly targeted in attacks on villages , '' he said . `` International donors and the government must urgently improve aid to these areas . ''
Aid groups : Peace deal signed in 2005 `` on the brink of collapse '' Aid groups : About 2,500 people killed , 350,000 fled in southern Sudan last year . U.N. : More people killed in southern Sudan in 2009 than in Darfur . Report : Protecting civilians should be core priority for U.N. peacekeepers .