The United Nations Refugee Agency has called for refugees and asylum seekers to be immediately removed from Nauru.
It comes as thousands of leaked incident reports published by Guardian Australia reveal allegations of sexual and physical abuse against women and children at the Nauru immigration detention centre.
The UNHCR says it has witnessed and reported on the deterioration of the situation in Nauru since 2012.
The allegations are consistent with its longstanding concerns regarding the conditions and mental health of refugees and asylum seekers on Nauru, it said in a statement on Wednesday.
"Delays in immediate action to rectify the current situation are exacerbating human suffering and causing ongoing deterioration."
One document discusses a painting created by a child asylum seeker that depicts "violent/intense sexual activity including the representation of a penis" and claimed that children had seen Nauruan guards pull their pants down and having sex.
A guard allegedly put his hands in the pants of an asylum-seeker child during a car trip, even though the father was present, according to another report.
