Detainees fear asylum seekers and refugees remaining at the mothballed Manus Island detention centre will resort to self harm after claims an Iranian man has already hurt himself.
About 600 men have barricaded themselves inside the centre which closed on Tuesday, with Iranian refugee Behrouz Boochani telling AAP the stress of the situation has led one of his countrymen to self harm.
The man's condition is stable, Mr Boochani said, after refugees rendered first aid because medical personnel are no longer at the centre.
"We (are) expecting that someone attack us ... nobody is here to protect us," he said.
"Starvation is pressuring and making the situation so worse ... we have no access to anything to survive."
There are fears of more self-harm incidents as the stand-off develops, especially as medications such as anti-depressants may soon run low.
There's also a threat of dysentery because the sewerage system has been cut off and the toilets are full.
The Lombrum centre was forced to close after the PNG Supreme Court ruled in April 2016 that Australia's detention of refugees and asylum seekers there was illegal and unconstitutional.
Electricity has so far been cut to at least half the buildings and, although there's an increased PNG military build up outside the centre, immigration officials have said they wouldn't be removing the men by force.
Acting Prime Minister Julie Bishop says it made "no sense" for detainees to remain in the centre, but she won't guarantee their safety if they leave the camp.
"The Papua New Guinea government is a sovereign government and is responsible for law and order and security on their islands in their nation," Ms Bishop told ABC radio on Wednesday.
Ms Bishop says food, water, electricity and medical services will be provided at alternative accommodation on the island.
Locals are reportedly blocking the construction of new refugee accommodation, with doubts about whether there are enough beds.
Greens senator Nick McKim, who is on Manus Island, has labelled Immigration Minister Peter Dutton a "monster" over his handling of the closure of the centre.
He warned deaths were inevitable and the minister "could have blood on his hands".
Mr Dutton on Tuesday attacked Senator McKim for spreading false information and inciting trouble in the tense final hours of the centre's shutdown.
"It's a badge of honour to be attacked by a racist, a fascist, a monster, and a serial abuser of human rights like Peter Dutton," Senator McKim told AAP from Manus Island on Wednesday.
Senator McKim said he was denied access to go inside on Wednesday with an "implied threat of arrest" if he stuck around the grounds.
The refugees and asylum seekers who remain inside the compound have little water left and their electricity generators have either been switched off or have run out of fuel.
The last food packs were distributed to them on Sunday night.
Tamil refugee Srirangan told AAP on Tuesday refugees were concerned about dehydration but feared for their lives as well, with troops from the mainland expected to arrive on Wednesday.
Some locals have looted tents, tables, boxes, fire alarms, fans and air conditioners from the decommissioned centre.
Australian aid groups have called on the Turnbull government to bring the men to Australia and "end their suffering".
Six detainees have died on Manus Island - including one who was murdered - since it was reopened in 2012.
Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.
Suicide Call Back Service 1300 659 467.
MensLine Australia 1300 78 99 78.
Multicultural Mental Health Australia www.mmha.org.au.
Local Aboriginal Medical Service details available from www.bettertoknow.org.au/AMS
