Disappearances and a resolution from the Security Council as well as mounting pressure from Amnesty International, ICRC and other human rights groups, the governments of Australia and New Zealand ceased providing military support, forcing Chan to begin to look elsewhere. Thus began the Sandline affair, where the government of Papua New Guinea attempted to hire mercenaries from Sandline International, a London-based private military company, composed primarily of former British and South African special forces soldiers, which had been involved in the civil wars in Angola and Sierra Leone. With negotiations with Sandline ongoing and incomplete, Chan ordered the military to invade anyway. In July the PNG defence forces attempted to seize Aropa airport, the island's principal airfield. However, the attack was a disaster, suffering from poor logistical planning and determined resistance by BRA fighters. In September, BRA militants attacked a PNG army camp at Kangu Beach with the help of members of a local militia group, killing twelve PNGDF soldiers and taking five hostage. The following month, Theodore Miriung was assassinated. Although Chan's government attempted to blame the BRA, a subsequent independent investigation implicated members of the PNG defence force and the resistance militias. Discipline and morale was rapidly deteriorating within the ranks of the PNG military, which had been unable to make any substantial progress in penetrating the mountainous interior of the island and reopening the Panguna mine. Chan decided that his best chance to recapture the Panguna mine was with the Sandline mercenaries. However, this too turned out to be a disaster. News of his intention to hire mercenaries was leaked to the Australian press, and international condemnation followed. Furthermore, when Jerry Singirok heard of the news, he ordered the detaining of all the mercenaries on arrival. In the resulting saga, Prime Minister Chan was forced to resign, and Papua New Guinea came very close to a military coup. Indeed, the officers in charge had the parliament surrounded, but steadfastly refused to go any further. In the end, however, they got their way, with Chan's resignation and the removal of the mercenaries from Papua New Guinean territory. Sandline sparked a low point in the Bougainvillean war. Since 1997, a ceasefire has largely held on the island. Breaking with Ona, Kauona and Kabui entered into peace talks with the government of Bill Skate in Christchurch, New Zealand, which culminated in the signing of the Lincoln Agreement in January 1998.