19, 1971, when one of the plotters, Major Hisham al Atta, surprised Nimeiri and the RCC meeting in the presidential palace and seized them along with a number of pro-Nimeiri officers. Atta named a seven-member revolutionary council, in which communists ranked prominently, to serve as the national government. Three days after the coup, however, loyal army units stormed the palace, rescued Nimeiri, and arrested Atta and his confederates. Nimeiri, who blamed the SCP for the coup, ordered the arrest of hundreds of communists and dissident military officers. The government subsequently executed some of these individuals and imprisoned many others. Having survived the SCP-inspired coup, Nimeiri reaffirmed his commitment to establishing a socialist state. A provisional constitution, published in August 1971, described Sudan as a "socialist democracy" and provided for a presidential form of government to replace the RCC. A plebiscite the following month elected Nimeiri to a six-year term as president. The Southern Problem The origins of the civil war in the south date back to the 1950s. On August 18, 1955, the Equatoria Corps, a military unit composed of southerners, mutinied at Torit. Rather than surrender to Sudanese government authorities, many mutineers disappeared into hiding with their weapons, marking the beginning of the first war in southern Sudan. By the late 1960s, the war had resulted in the deaths of about 500,000 people. Several hundred thousand more southerners hid in the forests or escaped to refugee camps in neighboring countries. By 1969 the rebels had developed foreign contacts to obtain weapons and supplies. Israel, for example, trained Anyanya recruits and shipped weapons via Ethiopia and Uganda to the rebels. The Anyanya also purchased arms from Congolese rebels and international arms dealers with monies collected in the south and from among southern Sudanese exile communities in the Middle East, Western Europe, and North America. The rebels also captured arms, equipment, and supplies from government troops. Militarily, the Anyanya controlled much of the southern countryside while government forces occupied the region's major towns. The guerrillas operated at will from remote camps. However, rebel units were too small and scattered to be highly effective in any single area. Estimates of Anyanya personnel strength ranged from 5,000 to 10,000. Government operations against the rebels declined after the 1969 coup. However, when negotiations failed to result in a settlement, Khartoum increased troop strength in the south to about 12,000 in 1969, and intensified military