At least eight refugees have moved from Papua New Guinea's Manus Island to Nauru.
A refugee protest at the East Lorengau Tranist Centre, 24-11-18. Photo: Behrouz Boochani
The Guardian reported the men voluntarily left on Thursday morning amid a worsening health crisis on Manus.
One of the men told the Guardian he did not know if Nauru would be any better but after more than five years on Manus he needed a change.
Australia currently detains more than 600 refugees on Manus and an unknown number of men, women and children on Nauru to deter others from seeking asylum in Australia.
Last week, the Refugee Council of Australia told RNZ Pacific refugees on Manus were feeling abandoned.
This followed a report the council co-authored detailing an increase in the number of self-harm and suicide attempts on Manus.