The relative peace between the South and the North following the armistice was interrupted by border skirmishes, celebrity abductions, and assassination attempts. The North failed in several assassination attempts on South Korean leaders, such as in 1968, 1974, and the Rangoon bombing in 1983; tunnels were found under the DMZ and tensions flared over the axe murder incident at Panmunjom in 1976. For almost two decades after the war, the two states did not seek to negotiate with one another. In 1971, secret, high-level contacts began to be conducted culminating in the 1972 July 4th North–South Joint Statement that established principles of working toward peaceful reunification. The talks ultimately failed because in 1973, South Korea declared its preference that the two Koreas should seek separate memberships in international organizations.