of atrocities in this war, although most of the blame has fallen on Arab militias (Janjaweed) allied with the government. The rebels have alleged that these militias have been engaging in ethnic cleansing in Darfur, and the fighting has displaced hundreds of thousands of people, many of them seeking refuge in neighboring Chad. There are various estimates on the number of human casualties, ranging from under twenty thousand to several hundred thousand dead, from either direct combat or starvation and disease inflicted by the conflict. In 2004 Chad brokered negotiations in N'Djamena, leading to the April 8 Humanitarian Ceasefire Agreement between the Sudanese government, the JEM, and the SLA. However, the conflict continued despite the ceasefire, and the African Union (AU) formed a Ceasefire Commission (CFC) to monitor its observance. In August 2004, the African Union sent 150 Rwandan troops in to protect the ceasefire monitors. It, however, soon became apparent that 150 troops would not be enough, so they were joined by 150 Nigerian troops. On September 18, 2004 United Nations Security Council issued Resolution 1564 declaring that the government of Sudan had not met its commitments, expressing concern at helicopter attacks and assaults by the Janjaweed militia against villages in Darfur. It welcomed the intention of the African Union to enhance its monitoring mission in Darfur and urged all member states to support such efforts. During 2005 the African Union Mission in Sudan force was increased to about 7,000. The Chadian-Sudanese conflict officially started on December 23, 2005, when the government of Chad declared a state of war with Sudan and called for the citizens of Chad to mobilize themselves against Rally for Democracy and Liberty (RDL) militants (Chadian rebels backed by the Sudanese government) and Sudanese militiamen who attacked villages and towns in eastern Chad, stealing cattle, murdering citizens, and burning houses. Peace talks between the southern rebels and the government made substantial progress in 2003 and early 2004, although skirmishes in parts of the south have reportedly continued. The two sides have agreed that, following a final peace treaty, southern Sudan will enjoy autonomy for six years, and after the expiration of that period, the people of southern Sudan will be able to vote in a referendum on independence. Furthermore, oil revenues will be divided equally between the government and rebels during the six-year interim period. The ability or willingness of the government to fulfill these