The Manus Island detention centre, which houses around 800 people, is due to be shuttered Tuesday after PNG's Supreme Court ruled last year that holding people there was unconstitutional.

Water and power will be cut off at the centre, one of two Pacific camps where asylum seekers who try to enter Australia by boat are sent for processing under Canberra's harsh immigration policy.

There are fears of a flashpoint situation if the men are forcibly moved to temporary transit facilities while their future is decided.

Amnesty International described the situation as "extremely tense" and stressed that all security workers "must abide by international obligations and refrain from excessive use of force".

"The Australian and Papua New Guinean governments must take all necessary steps to prevent violence against refugees from the community and ensure their safety," Amnesty Pacific researcher Kate Schuetze added.

PNG police commissioner Gari Baki said last week there was a "small disgruntled faction among the refugees" and pleaded with locals not to make the transfers difficult.

Asylum seekers on Manus are barred from settling in Australia even if they are found to be genuine refugees.

Instead, they have been given the option of moving to the other centre on the island of Nauru, returning to their homeland, settling in a third country like Cambodia, or making a life in PNG.

While the United States has accepted a handful of them under a deal struck with former president Barack Obama, Canberra has had little success relocating those on Manus and Nauru anywhere else.

Many have voiced fears for their safety if they chose to stay on PNG amid reports they would not be welcomed in local neighbourhoods.

PNG's Immigration Minister Petrus Thomas said in a statement there were unresolved issues about what happens to those who do not want to settle in PNG, and those who refuse to return home.

"PNG has no obligation under the current arrangement to deal with these two cohorts," he said.

"They remain the responsibility of Australia to pursue third-country options and liaise with respective governments of the non-refugees for their voluntary or involuntary return.

"There has to be a clear understanding of what Australia will continue to do and support PNG in the next few months to deal with the remaining caseload," he added.

Thomas said of those transferred to Manus under Australia's tough policies, nearly 600 had returned home voluntarily, seven were deported and five had died -- leaving 610 genuine refugees and 201 non-refugees on the island.

Source:AFP