UN warns that South Sudan faces ‘existential crisis’ ahead of uncertain polls

United Nations peacekeepers pass displaced South Sudanese near a camp in Malakal. UN troops are based at 27 sites but a review said 36 were needed. Photograph: Ben Curtis/AP

In a volatile region, few areas are more hostile than the flatlands surrounding the South Sudanese town of Abiemnom. Four miles north-east of it lies the border of the oil-rich Abyei region, where spasms of violence have left scores dead this year.

Slightly further on is the border with Sudan, which is engulfed in civil war. From there, the notorious paramilitary Rapid Support Forces are moving steadily closer.