Civilians caught up in Sudan's civil war have given graphic accounts to the BBC of rape, ethnic violence and street executions. Our journalists have managed to make it to the front line of the fighting close to the capital, Khartoum.
Top UN officials have said the conflict has plunged the country into "one of the worst humanitarian nightmares in recent history" and could trigger the world's largest hunger crisis.
There are also fears that in Darfur, in the west of the country, a repeat of what the US called genocide 20 years ago may be beginning to unfold.
