Papua New Guinea police have moved into the Manus Island detention centre to try to end a three-week stand-off with protesting asylum seekers and refugees.

Key points: Police moved in to remove more than 350 people from the centre

Police moved in to remove more than 350 people from the centre Malcolm Turnbull says men should "obey the law"

Malcolm Turnbull says men should "obey the law" Witnesses say refugees are crying and the authorities are "destroying everything"

The Australian-run centre closed last month and the occupants were asked to move to new facilities nearby.

But more than 350 men remain holed up there, because they say the new accommodation doesn't have adequate facilities and they fear for their safety.

PNG authorities have cut food, water and electricity and have told the remaining men they are squatters on defence force property.

Men inside the centre said local police who entered the centre today were aggressive and were destroying their belongings.

Prime Minister Malcolm Turnbull said the refugees and other detainees should obey the directions of PNG police.

"They think this is some way they can pressure the Australian Government to let them come to Australia," he said.

"We will not be pressured.

"They should obey the law... they should go peacefully and in accordance with the lawful direction of Papua New Guinea.

"There are alternative facilities that have been made available with food, water, security and medical services."

Police and immigration officials inside the Manus Island detention centre. ( Supplied )

Journalist arrested, PNG police 'destroying everything'

Men within the centre said PNG police had moved through the centre "destroying everything".

"They are destroying our rooms and throwing away our belongings," tweeted one man.

Iranian refugee and journalist Behrouz Boochani said PNG authorities were being "guided" by an Australian Federal Police (AFP) officer, a claim the AFP rejected.

"The AFP has no member within the former Manus Regional Processing Centre and no involvement in today's actions," it said in a statement.

Some detainees said PNG authorities had damaged their belongings at the centre. ( Supplied )

Another refugee later tweeted a photo which appeared to show Mr Boochani being led away by uniformed men.

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The MEAA, the Australian journalists trade union, issued a statement saying Mr Boochani had been arrested in what it said was an "attack on press freedom".

PNG police spokesman Dominic Kakas told the ABC the operation was being conducted by 10 PNG Immigration officials and around 40 police personnel.

He said around 35 non-refugees had decided to voluntarily leave the centre following the operation, and would move to the new facilities being provided.

"Immigration officials went in and explained to them that they really had no legal standing... voluntarily they packed their bags and moved across," he said.

"Police and immigration officials are still in the centre and they are basically talking to [the refugees and asylum seekers] and trying to reason with them."

Greens immigration spokesman Nick McKim said up to 100 PNG police officers were inside the centre and had been confiscating people's phones.

"There is a great degree of fear from the detainees there that violence will be perpetrated against them, they are determined to remain peaceful," Senator McKim said.

"But if there is violence and if blood is spilled it will because of the choices and decisions that Malcolm Turnbull and Peter Dutton have made."

'They've trashed the facility' : Dutton

Immigration Minister Peter Dutton told 2GB it was time for them to go.

"I think it's outrageous that people are still there and they have trashed the facility," he said.

"They're living in squalor.

"Some of them believe that if there is violence with police and the footage is broadcast back here that will twist our arm and change the policy position, but under no circumstance will these people be coming to Australia.

"The Australian taxpayers have paid about $10 million for a new facility and we want people to move."

Opposition Leader Bill Shorten called on the Government to accept a long-standing offer from New Zealand that would see them take 150 refugees from Australia's offshore detention centres.

"The Government has allowed this pressure-cooker to build over four years. And I just ask Malcolm Turnbull, please do the deal with New Zealand," he said.

"If New Zealand want to take some of these people and PNG and these people are happy to go to New Zealand, why are we getting in the way of a fair solution?"

'Too much stress and tension'

Authorities had previously said they would not use force to remove the men. ( Twitter: Abdul Aziz Adam, file )

Earlier Mr Boochani tweeted details of what was happening as police moved in

"Immigration and police started searching the rooms and are saying 'Move Move' you only have an hour to move," he wrote.

"Too much stress and tension here in Delta. Some refugees are crying."

Mr Boochani told the ABC's Pacific Beat that authorities had thus far not been physically violent, but were certainly upping the ante.

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"The police and immigration authorities don't have any weapons, they are [just abusing] the refugees to leave", Mr Boochani said from the centre.

"They just attacked here and they are saying that you must move at this time."

Mr Boochani said the alternative accommodation offered by Mr Dutton was not suitable.

"So we are refusing to leave this prison camp because we don't want to live in prison," he said.

"We didn't come to Australia to live in prison forever."