At least two and a half million people have fled their homes in fear of the government-backed Arab Janjaweed militia in Darfur. Despite the ongoing crisis, there are signs of progress in the North.
We were halfway across a valley in rebel-controlled North Darfur when the first shots were fired, apparently from a nearby hill.
Soon they were coming thick and fast.
Our driver stopped. We all got out and hid, as best we could, behind our vehicle.
It was painfully clear that we were being shot at - not over.
Patrolling the valley
Our escort, a law graduate from Khartoum University who is now a commander in the Sudan Liberation Army (SLA) - the main rebel group in Darfur - eventually located the source of fire and determined that it was friendly fire.
He walked towards the attackers with his hands in the air.
To us, crouching behind the car with bullets flying all around, it seemed as if he walked for ever.
Finally, the shooting stopped and our escort returned.
He explained that an SLA commander patrolling the valley on the look out for government forces, had thought we were Janjaweed: militiamen who move on horse and camelback but who occasionally have vehicles similar to those of the government forces.
We were returning from a village that had been burned by the Janjaweed in 2003, at the very beginning of the war in Darfur.
The Janjaweed are accused of ethnic cleansing
The village is still uninhabited.
Perhaps understandably, we were mistaken for the enemy.
It was a very unnerving 15 minutes or so.
But it was the only time we heard shots fired in anger in more than three weeks behind rebel lines in North Darfur.
A catastrophe of almost unimaginable proportions has engulfed Darfur in the five years since the rebels took up arms to fight for an end to marginalisation and oppression, and for an end to government support for Arab militias.
Gun emplacement trenches in the sandy plains of North Darfur
The statistics are terrifying, yet statistics do not tell the whole story.
There are some encouraging signs in some rebel-controlled areas of Darfur.
Especially in the areas that I visited: the part of North Darfur that is controlled by rebels who reject the peace agreement signed last year by the government and one rebel group - the faction of the SLA that is controlled by Minni Minawi.
Committed to peace talks
Since Minawi signed the Darfur Peace Agreement, his forces have been expelled from rural North Darfur.
The rebel commanders who have replaced him are not completely united, but they have a unity of purpose that is encouraging, and that marks a clear break with the often criminal behaviour of Minawi's men.
The men now in charge want a negotiated solution to the war and are committed to new peace talks - if, and it is a big "if" - the SLA can unite behind a common platform all across Darfur. Not just in the north.
They have begun making overtures to neighbouring Arab tribes who have been fighting against them and have abolished the crippling taxes that Minawi imposed on civilians - civilians already pushed to the brink by the death and devastation heaped upon them by the government and its Janjaweed allies.
They have stopped bringing civilians in front of military courts and have begun asking community leaders to re-open the civilian courts that Minawi closed.
In the village of Bakaore, I met Omda Hamid Manna, a chief who once presided over one of the most important civilian courts in North Darfur, in the village of Dor.
He related how he had been kidnapped by Minawi's men, tortured and only released after payment of a whopping ransom.
A few days before we met, he had been approached by the SLA faction that ousted Minawi and asked to re-open his court.
Some power was being handed back to civilians, and he was jubilant.
"Minawi did very bad things," he said. "He took our animals and collected our money. He took food aid from civilians. If you protested, you were beaten or killed. But the SLA is good now. It is not taking away our rights."
Late last year, the government tried to recapture the parts of North Darfur that are controlled by Minawi's opponents. It failed.
The sandy plains surrounding the village of Um Sidir bear witness to the magnitude of its defeat.
For as far as the eye can see, the sands are covered in half-buried skeletons, brightly coloured toothbrushes and piles of weapons that were abandoned as Khartoum's men ran for their lives on the 9 September 2006.
The skeleton of a government commander lies on the sand in Um Sidir
Signs of progress
Only one government commander did not flee when the rebels attacked, with the sun behind them shining straight into their enemy's eyes.
Today his burnt and cannibalised car stands alone in the middle of the battlefield.
We buried what we thought was his body as best we could with the only thing to hand - a piece of cardboard.
Since then, violence in this part of Darfur has decreased significantly.
People are terrified of the Janjaweed but no longer, on the whole, afraid of their own rebel movement.
It is not a peace, and what it is is fragile, and localised. But it is a beginning and it deserves recognition and encouragement.
From Our Own Correspondent was broadcast on Thursday 14 June , 2007 at 1100 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.