As opposition to Diệm's rule in South Vietnam grew, a low-level insurgency began to take shape there in 1957. Finally, in January 1959, under pressure from southern Viet Cong cadres who were being successfully targeted by Diệm's secret police, Hanoi's Central Committee issued a secret resolution authorizing the use of armed insurgency in the South with supplies and troops from the North. On 20 December 1960, under instructions from Hanoi, southern communists established the Viet Cong (NLF) in order to overthrow the government of the south. On 11 November 1960, "a failed coup attempt against President Ngô Đình Diệm of South Vietnam was led by Lieutenant Colonel Vương Văn Đông and Colonel Nguyễn Chánh Thi of the Airborne Division of the ARVN (ARVN)". There was a further attempt to assassinate Diệm and his family in February 1962 when two air force officers—acting in unison—bombarded the Presidential Palace.