of the rally the ABAKO leadership told the crowd that had gathered that the event was postponed and that they should disperse. The mass was infuriated and instead began hurling stones at the police and pillaging European property, initiating three days of violent and destructive riots. The Force Publique, the colonial army, was called into service and suppressed the revolt with considerable brutality. In wake of the riots Kasa-Vubu and his lieutenants were arrested. Unlike earlier expressions of discontent, the grievances were conveyed primarily by uneducated urban residents, not évolués. Popular opinion in Belgium was one of extreme shock and surprise. An investigative commission found the riots to be the culmination of racial discrimination, overcrowding, unemployment, and wishes for more political self-determination. On 13 January the administration announced several reforms, and the Belgian King, Baudouin, declared that independence would be granted to the Congo in the future. Meanwhile, discontent surfaced among the MNC leadership, who were bothered by Lumumba's domination over the party's politics. Relations between Lumumba and Kalonji also grew tense, as the former was upset with how the latter was transforming the Kasai branch into an exclusively Luba group and antagonising other tribes. This culminated into the split of the party into the MNC-Lumumba/MNC-L under Lumumba and the MNC-Kalonji/MNC-K under Kalonji and Iléo. The latter began advocating federalism. Adoula left the organisation. Alone to lead his own faction and facing competition from ABAKO, Lumumba became increasingly strident in his demands for independence. Following an October riot in Stanleyville he was arrested. Nevertheless, the influence of himself and the MNC-L continued to grow rapidly. The party advocated for a strong unitary state, nationalism, and the termination of Belgian rule and began forming alliances with regional groups, such as the Kivu-based Centre du Regroupement Africain (CEREA). Though the Belgians supported a unitary system over the federal models suggested by ABAKO and CONAKAT, they and more moderate Congolese were unnerved by Lumumba's increasingly extremist attitudes. With the implicit support of the colonial administration, the moderates formed the Parti National du Progrès (PNP) under the leadership of Paul Bolya and Albert Delvaux. It advocated centralisation, respect for traditional elements, and close ties with Belgium. In southern Léopoldville Province, a socialist-federalist party, the Parti Solidaire Africain (PSA) was founded. Antoine Gizenga served as its president, and Cléophas Kamitatu was in charge of the Léopoldville Province chapter. The Belgo-Congolese Round Table Conference After the