Prime Minister Patrice Lumumba, dissatisfied with Dag Hammarskjöld's refusal to use UN troops to subdue the insurrection in Katanga, decided to attempt an invasion of Katanga on his own and turned to the Soviet Union for help. The invasion attempt never reached Katanga but led to dissension within the Central Government, the collapse of the Central Government, and eventually to Lumumba's arrest in December. Lumumba was then executed in Katanga in January 1961. Only then did the United Nations Security Council explicitly authorize the use of force for purposes beyond self-defense.