Asylum seekers who are refusing to leave an Australian detention centre in Papua New Guinea say they are digging into the ground to find water, two days after the camp officially closed.
About 600 men at the centre on Manus Island do not want to leave, saying they fear being attacked outside.
Meanwhile, New Zealand has reiterated its offer to accept up to 150 refugees from Australia's detention centres.
Canberra has repeatedly rejected New Zealand's offer.
Australia holds asylum seekers who arrive by boat on PNG's Manus Island, and on the Pacific island of Nauru.
Australia withdrew from the Manus Island centre on Tuesday, following a PNG court ruling that the centre was unconstitutional.
The men held at PNG - most of whom have refugee status - have now lost access to running water, electricity and working toilets, and their food supplies are dwindling.
The UN refugee agency has said some alternative accommodation is not ready.
The agency and rights groups have warned that the men have legitimate fears for their safety, and that attacks on asylum seekers have occurred in the past in PNG.
Refugees told the BBC that they had dug into the ground and set up catchments to collect rainwater, but much of it was being stored in rubbish bins.
They said that PNG immigration officials arrived outside the centre on Wednesday, and they feared being forcibly removed.
Under its controversial policy, Australia refuses to take in anyone trying to reach its territories unofficially by boat. The government says its policy prevents human trafficking and deaths at sea.
New Zealand reiterates offer
Amid the escalating stand-off, the New Zealand government said a standing offer to accept 150 refugees from Manus Island or Nauru "remains on the table".
The proposal has been repeatedly rejected by Canberra since it was first made in 2013.
"I think anyone would look at a situation like that and see the human face of what is an issue that New Zealand is in the lucky position of not having to struggle with, and Australia has," New Zealand Prime Minister Jacinda Ardern said on Thursday.
Ms Adern said she would raise Manus Island with Australian Prime Minister Malcolm Turnbull when the two meet in person on Sunday.
Last year, Mr Turnbull said people smugglers would use any such deal with New Zealand as a "marketing opportunity".
His government has said it makes "no sense" for the detainees to remain in the centre when there was alternative accommodation, although it would not guarantee their safety in the local community.
Nat Jit Lam, the UN High Commissioner for Refugees (UNHCR) regional representative, said on Wednesday that some of that accommodation was not yet fit to live in.
"I will not be bringing any refugee there to stay - not in that state," he said.
Photo copyright: BEHROUZ BOOCHANI (Caption: Asylum seekers have dug holes in the ground, hoping to find fresh water)