16 September. On 1 September, they issued the 'Unilateral Declaration of Independence of the Republic of North Solomons'. They sought international recognition through the United Nations, but were unsuccessful. They also failed in an attempt to unite with the Solomon Islands. In early 1976, the Bougainvillean government realised that they would have to accept Papua New Guinean sovereignty. Later that year, both the governments signed the 'Bougainville Agreement', which gave the island autonomy within Papua New Guinea. The PNG government promised full independence in five years, but did not fulfill this promise. For the remainder of the 1970s, and into the early 1980s, relations between the two remained tense, but relatively peaceful. In 1981 disputes re-emerged over the status of the mine, which was the basis of the conflict that became violent in 1988. Secessionist conflict Tensions Operations of the mine at Panguna and sharing of its revenues had been perhaps the major sticking point between Bougainville and PNG government. The mine was the largest non-aid revenue stream of the Government of Papua New Guinea from 1975, when it became independent, to the mine's closure in 1989. The national government received a 20% share of profit from the mine and authorised 0.5–1.25% share to the Bougainvilleans. Revenues from the mine products was vitally important to the economy of Papua New Guinea, but the people of Bougainville were seeing little benefit from it. In addition, they began to recognise that they were bearing the total effects of the mine's environmental consequences for the island. They claimed that the Jaba River had been poisoned, causing birth defects among local people, as well as the extinction of the flying fox on the island and adverse effects on fish and other species. Critics said that Bougainville Copper had created an apartheid, segregated system, with one set of facilities for white workers, and one set for the locals. Insurgency By late 1988, cousins and local leaders, Francis Ona and Pepetua Serero, decided to take up arms against the Papuan government. Ona had worked for Bougainville Copper, and had witnessed the effects the mine was having on the environment. In 1987, Ona and Serero had called a meeting of landowners around Panguna, forming the Panguna Landowners' Association. Serero was selected as 'Chairlady' and Ona as General Secretary. They demanded billions in compensation from CRA for lost revenues and damages, a total of half the mine's profits