Sudanese President Omar Hassan al-Bashir has ordered "complete mobilisation" to disarm all illegal armed groups in the western region of Darfur, including the Arab militias who have been harassing African villagers.
A statement released by the Sudanese presidency said all government agencies should mobilise "to control and pursue all outlaw groups, including rebels and Janjaweed..., disarm the outlaws and present them to justice and prevent any groups from crossing into neighbouring Chad".
The Janjaweed is the local word for the Arab militias whom the Darfur rebels blame for much of the conflict in the region.
The rebels say the government has backed the Janjaweed but the government has repeatedly denied that.
International organisations have criticised the Sudanese government for failing to control the militias, who have driven hundreds of thousands of Africans out of their villages into camps for displaced persons or into exile in Chad.
The United States threatened on Friday to impose sanctions on Sudanese officials as a way of intensifying the pressure to help ease a humanitarian crisis in Darfur.