Another 40 men have been transferred to an offshore processing centre, this time to Manus Island.

It follows 30 men being moved to the offshore processing centre on Nauru earlier on Saturday.

The single men, mostly Iranians, Iraqis and Afghans, arrived at the Papua New Guinean island about 1230 (AEDT) on Saturday, the Department of Immigration and Citizenship (DIAC) said in a statement.

The group went through relevant immigration, customs and quarantine processes before being moved to the centre on the island.

DIAC said transfers would continue as part of the government's policy of regional processing and that there would be no advantage for those people arriving in Australia by boat.