Now in the grip of fresh conflict, what began as a political dispute has polarised along ethnic lines, with the ruling Dinka-dominated Sudan Peoples’ Liberation Movement (SPLM) fast disintegrating as diverse militia take control of oilfields and prospective provinces.

Skirmishing has rippled out from the capital Juba to the tinderbox town of Bor where, in 1991, thousands of Dinka civilians were massacred by militia led by former vice president Riek Machar — sacked by head of state Salva Kiir after serving eight years.

Machar