Refugees have been staging protests and a campaign of non-cooperation, amid growing tension with locals.
President Baron Waqa said advocate groups were stirring up trouble for their own political agendas.
“Refugees are safe in the country and talk to the contrary is blatant lies spread by Australian advocates and lawyers,” he said, in a statement.
“We believe they are being directed by faceless people in Australia.”
The government was sensitive to the grievances of refugees but would not accept violence or law breaking, Waqa said.
Activists claim 300 refugees rallied last Friday and five were slightly injured when they were blockaded by police.
The Nauru government insists only 150 refugees took part in a demonstration and that refugees threw stones at officers, injuring three and damaging a police car.
“There has been no violence against refugees from police, but police will continue to enforce the law, which includes preventing mobile protests that endanger lives,” Waqa said.
He also dismissed allegations refugee children had been raped.
“Police say it is unlikely, as minors are always accompanied by parents and care workers.”
The Refugee Action Coalition maintains the ongoing protest movement is peaceful and that refugees want to show their disgust at “being treated like slaves”.