At least eight refugees have moved from Papua New Guinea's Manus Island to Nauru.
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.
A refugee was taken to hospital after he attended to suicide The condition is worsening. Attempts of suicide is escalating on Manus. pic.twitter.com/9PsWymjzlS
— Shamindan (@Shamindan1) November 27, 2018
The conditions of sick refugees at Lorengau general hospital is getting worse each day & they’re only surviving on drips neither of them is able to eat or drink.They have built up a withdrawal syndrome lost hope of living or eating, drinking & speaking they disengaged completely.
— Abdul Aziz Adam (@Abdulaziz_Ada) November 29, 2018