Tribal clashes in Papua New Guinea's highlands have left at least 19 people dead, including seven who were killed by a grenade, authorities said Monday.

Australia has launched a new bid to be elected to the United Nations Security Council, with Foreign Minister Julie Bishop saying the nation hoped to maintain its focus on international security.

Bishop said in a statement Wednesday that Australia would be a candidate for a Security Council seat in 2029-30 as she signaled the country's intention to also seek a spot on the U.N. Human Rights Council for 2018-20.

Australia's new Prime Minister Malcolm Turnbull Wednesday admitted he had concerns about asylum seekers being held in Pacific island camps, but gave no indication of immediate change to the hardline policy.

All asylum seekers coming by boat to Australia are sent to camps in Papua New Guinea and Nauru and ultimately denied resettlement in Australia even if they are found to be genuine refugees.

An Australian immigration camp on the Pacific island of Nauru is inadequate and unsafe, a Senate committee said Monday as it called for the government to remove children from the center.

Submissions to the inquiry, which the government has dismissed as a political "stunt", have included allegations of rape and other abuse at the camp which is funded by Australia.

Papua New Guinea Prime Minister Peter O'Neill Sunday pledged his nation's support in tackling human trafficking as he confirmed the seizure of a boat carrying alleged slaves from Cambodia and Myanmar.

O'Neill said the eight people were rescued from the fishing boat "Blissful Reefer" after it was boarded on July 27 off the southern port of Daru in PNG waters.

Australian authorities work within the law to stop asylum-seeker boats, Prime Minister Tony Abbott insisted Tuesday after reports officials have made cash payments to members of people-smuggling rings for years.

The government has refused to deny reports that six Indonesian crew members were paid $US5,000 each to return an asylum-seeker vessel to Indonesia in late May, saying no comment will be made on operational issues.

Indonesia's vice president warned Monday that paying people-smugglers would amount to "bribery" after Australia was accused of handing out money to turn back a boatload of asylum-seekers.

Allegations that the captain and five crew of a boat, carrying migrants from Bangladesh, Myanmar and Sri Lanka, were each paid US$5,000 by an Australian immigration official to turn back to Indonesia were made to police on Rote island in the country's east last week.

Prime Minister Tony Abbott said Friday Australia would do "whatever we need to do" to combat people-smuggling as he repeatedly refused to deny claims an official paid thousands of dollars to turn back a boat from Indonesia.

Indonesian authorities said they were investigating allegations told to local police that the captain and five crew of a boat carrying asylum-seekers were each paid US$5,000 by an Australian immigration official to return to the Southeast Asian nation.

Cambodia received its first batch of asylum-seekers from Australian custody on Thursday, with rights groups labeling them "human guinea pigs" for an uncaring policy by Canberra to offload refugees onto other countries.

The migrants -- three Iranians and one ethnic Rohingya from Myanmar -- were flown into Phnom Penh, the capital of one of Southeast Asia's poorest nations with a weak record of upholding human rights.

The Pacific nation of Papua New Guinea must crack down on crimes against people suspected of sorcery after a mob hacked a woman to death this week, Amnesty International said Wednesday.

The rights group said the death of the woman, identified only as Misila, on Tuesday in a remote part of the Highlands area of the often lawless country underlined the imminent risk to those accused of witchcraft.