The United Nations has called for calm after a group of asylum seekers were detained by PNG police and dozens more removed from the decommissioned Manus Island detention centre.
Immigration Minister Peter Dutton confirmed Iranian refugee and journalist Behrouz Boochani was among a "small number" arrested by officers who entered the complex on Thursday.
Mr Boochani, who was later released, claimed former detainees were "under attack" from police and immigration officials who were upturning the men's rooms, confiscating phones and demanding they leave immediately.
"UNHCR reminds Australia of its obligation to take full responsibility and provide effective protection, safety and lasting solutions for all refugees and asylum-seekers in cooperation with the Papua New Guinean authorities", said UNHCR Assistant High Commissioner for Protection Volker Turk.
"We urge both governments to engage in constructive dialogue, to de-escalate the tensions and work on urgent lasting solutions to their plight."
The refugees and asylum seekers have occupied the centre for the three weeks since its closure and refuse to move to alternative accommodation the Australian government says is equipped with medical supplies, food and power.
"We would expect the number which, up until this morning had been about 370 people within that centre, would drop well below that now," Mr Dutton told Sky News on Thursday.
"The operation is still underway but it is important that we get people out of the regional processing centre into much better accommodation as quickly as possible."
The government didn't want people living in the centre, he said.
"The Australian taxpayers have paid about $10 million for a new facility and we want people to move," Mr Dutton told Sydney's 2GB radio earlier.
World Vision chief advocate Tim Costello, who is on Manus Island, called on Prime Minister Malcolm Turnbull to bring the "unfolding humanitarian crisis" to a swift and humane resolution.
"Malcolm Turnbull is not a cruel man, he is not inhumane, but what we are witnessing here is both cruel and inhumane," Mr Costello said.
"I think personally he'd be appalled if he was seeing what we are witnessing."
The refugees and asylum seekers have refused to leave, citing safety fears at the alternative accommodation 20km away at Lorengau which they say is unfinished.
