Sept 27 (Reuters) - Sudan and South Sudan signed deals on Thursday to secure their shared border and boost trade, but failed to resolve other conflicts remaining after the South seceded last year.
Here is a look at areas along the 1,800 km (1,200 mile) boundary where tensions remain high.
* ABYEI: The fertile central region is claimed by both Sudan and South Sudan and their armies have clashed there a number of times. Abyei's residents were promised a referendum on which country to join under the same deal that granted the South its independence last year. But that vote has not materialised.
* Abyei is a microcosm of all the conflicts that have split the region for decades, an explosive mix of ethnically divided communities, ambiguous boundaries, oil and age-old suspicion and resentment.
* As demanded in a U.N. Security Council resolution, both sides have pulled their armed forces out of the area which is now patrolled by an Ethiopian-led U.N. force (UNISFA) of around 3,800 peacekeepers.
* SOUTH KORDOFAN: South Kordofan was at one stage inhabited by at least 2.5 million people from more than 100 ethnic communities. But it is difficult to make an accurate estimate of the current population as hundreds of thousands have fled recent fighting between rebels of the SPLM-North and Sudan's army. South Kordofan lies on the Sudanese side of the border. But the oil-producing state is also home to thousands of fighters who sided with the South against Khartoum during the last civil war.
* HEGLIG: Global powers widely condemned South Sudan's brief seizure of Heglig oil field in South Kordofan in April. South Sudan said it took the oil-field in self defence, accusing Sudan of using the area as a base to launch attacks on southern territory. Heglig produced about half of Sudan's oil output of 115,000 barrels per day (bpd) before the clashes.
* BLUE NILE: Sudan's Blue Nile state is home to many supporters of the South's dominant Sudan People's Liberation Movement.
* OTHER DISPUTED ARES: At least five border areas are disputed by the two nations but the African Union failed to broker a deal at the latest round of talks, leaving the issue to future negotiations or international arbitration.
Sources: Reuters/UNHCR/www.insightonconflict.org/AllAfrica/HRW (Reporting by David Cutler, London Editorial Reference Unit) (Editing by Louise Ireland)