While the world's attention has focussed on the conflict in Darfur, an older and even bloodier conflict between the Muslim north and mainly Christian south of Sudan is in danger of re-igniting.
Four years after a peace deal was agreed, Grant Ferrett travels to Southern Sudan to investigate claims that Africa's biggest nation is sliding back to civil war.
BBC Radio 4's Crossing Continents: Southern Sudan is broadcast on Thursday, 6 August, 2009 at 1102 BST and is repeated on Monday, 10 August, 2009 at 20:30 BST.
Reporter: Grant Ferrett
Producer: Andy Denwood