* Human rights organisations say militias known as the Janjaweed, with the connivance of the Sudanese army, are driving farmers from their land in a deliberate campaign of ethnic cleansing, verging on genocide. The Sudanese government says the Janjaweed are outlaws and it is determined to disarm them.
* The Janjaweed, mounted on camels and horses, have set fire to villages, killed many of the men and raped women and girls.
* More than one million Muslim Darfuris, mainly subsistence farmers from a wide variety of ethnic groups and many of whom share the Arabic tongue of their northern compatriots, have fled their homes, creating what the United Nations has described as the world's worst humanitarian crisis.
Two groups in Darfur are in an
armed conflict with government
* Most of them have taken refuge in camps in Darfur but more than 150,000 of them have crossed into Chad as refugees.
* Nomads have been encroaching on farming communities in Darfur for many years and the Janjaweed campaign is an extension of that migration.
* In February 2003, two rebel groups mainly from the African Zaghawah, Masalit and Fur tribes in Darfur took up arms against the government, arguing Khartoum had neglected the vast region and was failing the protect the people from the militias.
* Since the tribes live on both sides of the border, there is a danger that the conflict could spill over into neighbouring Chad. Chadian opponents of President Idris Debi have been accused of exploiting the conflict to try and destabilise his regime.
* The prospect of peace in a separate conflict in the south of Sudan may have emboldened the rebels to believe they could win a better deal by resorting to arms, analysts say.
* The Sudanese government has restricted humanitarian access to Darfur and relief organisations now say they are racing against time to get supplies in place before the rainy season.
*US secretaryof state Colin Powell and UN Secretary general Kofi Annan are threatening UN Security Council action against the Sudanese government if it does not stop the Janjaweed and allow free access for relief organisations.