FACTBOX-What’s happening in western Sudan.

KHARTOUM, Aug 11 (Reuters) – Helicopter attacks, raids on refugee camps and rapes carried out by Sudanese forces and Arab militiamen have worsened an already desperate situation in Darfur, rights groups said on Wednesday.

Here are the main facts about the conflict:

– Human rights organisations say Arab 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.

– More than 1 million Muslim Darfuris, mainly subsistence farmers from a wide variety of ethnic groups for whom Arabic is a second language, have fled their homes.

– Most of them have taken refuge in camps in Darfur but some 200,000 of them have crossed into Chad as refugees.

– Arab nomads have been encroaching on farming communities in Darfur for many years and the Janjaweed campaign is an extension of that migration, accelerated by the government’s ideological commitment to Arabisation in the 1990s.

– In February 2003, two rebel groups 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.

– 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.

– In a July 30 U.S.-drafted resolution, the Security Council gave Khartoum 30 days to take measures against the Janjaweed, or face unspecified sanctions. U.N. Secretary-General Kofi Annan is to report on compliance with the resolution within 30 days.

– The United Nations estimates Darfur violence has killed 50,000 and made two million short of food and medicine. Khartoum disputes the death toll.

– Human Rights Watch said on Wednesday fresh atrocities disproved Sudanese government claims that security was returning to the western region.