movements in Sarawak ceased after a clamp-down by the colonial government. On 27 May 1961, Tunku Abdul Rahman, the prime minister of the Federation of Malaya, announced a plan to form a greater federation together with Singapore, Sarawak, North Borneo and Brunei, to be called Malaysia. On 17 January 1962, the Cobbold Commission was formed to gauge the support of Sarawak and Sabah for the plan; the Commission reported 80 per cent support for federation. On 23 October 1962, five political parties in Sarawak formed a united front that supported the formation of Malaysia. Sarawak was officially granted self-government on 22 July 1963, and became federated with Malaya, North Borneo (now Sabah), and Singapore to form a federation named Malaysia on 16 September 1963. The governments of the Philippines and Indonesia opposed the new federation, as did the Brunei People's Party and Sarawak-based communist groups, and in 1962, the Brunei Revolt broke out. Indonesian President Sukarno responded by deploying armed volunteers and, later, military forces into Sarawak. Thousands of Sarawak communist members went into Kalimantan, Indonesian Borneo, and underwent training with the Communist Party of Indonesia. The most significant engagement of the confrontation was fought at Plaman Mapu in April 1965. The defeat at Plaman Mapu ultimately resulted in the fall of Sukarno and he was replaced by Suharto as president of Indonesia. Negotiations were restarted between Malaysia and Indonesia and led to the end of the confrontation on 11 August 1966. A number of communist groups existed in Sarawak, the first of which, the Sarawak Overseas Chinese Democratic Youth League, formed in 1951. Another group, the North Kalimantan Communist Party (NKCP) (also known as Clandestine Communist Organisation (CCO) by government sources) was formally set up in 1970. Weng Min Chyuan and Bong Kee Chok were two of the more notable communist leaders involved in the insurgency. As the political scene changed, it grew progressively more difficult for the communists to operate. This led to Bong opening talks with chief minister Abdul Rahman Ya'kub in 1973 and eventually signing an agreement with the government. Weng, who had moved to China in the mid-1960s but nonetheless retained control of the CCO, pushed for a continued armed insurrection against the government in spite of this agreement. The conflict continued mostly in the Rajang Delta region but eventually ended when, on 17 October 1990, the NKCP signed a peace agreement with the Sarawak