on the progress and conduct of the war. Negotiations were proposed in late March, and on 2 April a new Prime Minister of Zaire, Étienne Tshisekedi—a longtime rival of Mobutu—was installed. Kabila, by this point in control of roughly one-quarter of the country, dismissed this as irrelevant and warned Tshisekedi that he would have no part in a new government if he accepted the post. There are two explanations for the restart of the rebel advance in 1997. The first, and most probable, is that Angola had joined the anti-Mobutu coalition, giving it numbers and strength far superior to the FAZ, and demanding that Mobutu be removed from power. Kagame presents another, possibly secondary, reason for the march on Kinshasa: that the employment of Serbian mercenaries in the battle for Walikale proved that "Mobutu intended to wage real war against Rwanda." According to this logic, Rwanda's initial concerns had been to manage the security threat in eastern Zaire but it was now forced to dispose of the hostile government in Kinshasa. Whatever the case, once the advance resumed in 1997, there was virtually no meaningful resistance from what was left of Mobutu's army. Kabila's forces were only held back by the dreadful state of Zaire's infrastructure. In some areas, no real roads existed; the only means of transport were infrequently used dirt paths. The AFDL committed grave human rights violations, such as the carnage at a refugee camp of Hutus at Tingi-Tingi near Kisangani, where tens of thousands of refugees were massacred. Coming from the east, the AFDL advanced westward in two pincer movements. The northern one took Kisangani, Boende, and Mbandaka, while the southern one took Bakwanga, and Kikwit. Around this time, Sudan attempted to coordinate with remnants of the FAZ and White Legion that were retreating northward to escape the AFDL. This was to prevent Zaire from becoming a safe haven for the Sudan People's Liberation Army (SPLA) and its allies, which were fighting the Sudanese government in the Second Sudanese Civil War at the time. The Mobutu-loyal forces were collapsing so quickly, however, that they could not prevent the AFDL, SPLA and Ugandan military from occupying northeastern Zaire. Sudan-allied Ugandan insurgent groups which had been based in the region were forced to retreat into southern Sudan alongside FAZ troops that had not yet surrendered and a smaller number of Sudanese Armed Forces (SAF) soldiers. They attempted to