Immigration Minister Scott Morrison has confirmed that staff at the Manus Island detention centre were moved to safety after an incident this morning.

Mr Morrison was pressed for information during his weekly briefing after the Asylum Seeker Resource Centre reported that employees were evacuated due to security concerns.

"There was an incident earlier today on Manus Island and appropriate steps were taken to ensure staff were placed in safety," Mr Morrison says.

He has refused to be drawn on the details of the incident and says it's a matter involving agencies of the Papua New Guinea government.

"That is a matter for the Papua New Guinean government to address," he said.

He says all necessary steps have been taken to ensure Australian staff are safe.

After the briefing, Mr Morrison was forced to put out a statement saying he had been misinformed about the Manus Island evacuation, specifically that staff had been moved to a nearby naval vessel, the HMAS Choules.

In the statement, he said he had since been told no staff had been removed to the HMAS Choules.

Despite this, Mr Morrison used the once-weekly briefing to admonish assembled journalists for misreporting asylum seeker issues, including the widely cited presence of an asylum seeker on Nauru who is expecting twins.

"Again, this suggestion that there's a pregnant woman with twins on Nauru is simply not true, it's actually not true," he said.

"There is not a pregnant woman with twins on Nauru. And this is why I'm stressing to you."

He added: "I strongly suggest that media should more thoroughly interrogate the sorts of claims that are being represented to you. I mean that is a classic example."

73 asylum seekers flown home to Sri Lanka

The Government has revealed that 73 asylum seekers were immediately flown back to Sri Lanka following an initial assessment on Christmas Island.

The Operation Sovereign Borders weekly briefing revealed 167 asylum seekers tried to enter Australian waters on three boats in the past week.

The operational commander, Lieutenant General Angus Campbell, says these arrivals included a boat carrying 79 people from Sri Lanka which was intercepted last Saturday.

He says authorities found none of these people had reasons to seek refuge in Australia.

And that their removal would be consistent with Australia's protection obligations.

Seventy-three of these people have been returned to Sri Lanka.

The remainder are being assessed as to their fitness to fly with a view to returning them to Sri Lanka as soon as possible.