Belgium's brutal exploitation continued until a wave of nationalistic riots in the 1950s prompted it to abandon the region and grant Congo independence in June of 1960. Civil war erupted soon after, when the southeastern Katanga province, led by activist Moise Tshombe, seceded from the new republic in July. With President Joseph Kasavubu and Prime Minister Patrice Lumumba at odds, Belgian troops returned - this time under the auspices of the United Nations - to quell the war. Kasavubu led an army coup later that same year, dismissed Lumumba from his position, and handed him over to the Katangan forces. Lumumba was murdered in February, 1961, reportedly with the complicity of the United States and Belgium, who were threatened by Lumumba's ties to the Soviet Union. Soon after, Tshombe agreed to end Katanga's secession, and he was appointed prime minister by President Kasavubu in an effort to prevent another rebellion.