Manus Island refugees 'expecting someone to attack us'

Detainees fearful of their safety and deteriorating wellbeing at the mothballed Manus Island are scared of what's to come.

Around 600 men have barricaded themselves inside the centre, which closed on Tuesday, with Iranian refugee Behrouz Boochani telling AAP the men are living in fear somebody will attack them.

"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."

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.

The men spent the night in complete darkness on Wednesday as power was cut and drank what rainwater they had collected earlier in the day.

There's also a threat of dysentery because the sewage system has been cut off and the toilets are full.

The pressure mounted so high, it led to one of Mr Boochani's countrymen to self harm, Mr Boochani said.

The man's condition is stable, he said, after refugees rendered first aid because medical personnel are no longer at the centre.

There are fears of more self-harm incidents as the stand-off develops, especially as medications such as anti-depressants may soon run low.

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.

Ms Bishop says food, water, electricity and medical services will be provided at alternative accommodation on the island.

But, authorities face a stand-off with detainees unwilling to go and locals are reportedly blocking the construction of new refugee accommodation.

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.

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

Australian readers seeking support and information about depression can contact Lifeline on 13 11 14.