Three schoolgirls have been attacked in their classroom at Nauru's high school in what the Refugee Action Coalition says is the latest attempt to intimidate refugees.
The Coalition says the girls were set upon by about 15 Nauruan boys.
It says one suffered bruising in the attack which also left windows in the school broken.
The more than 100 asylum seekers whose refugee status has been accepted have been officially encouraged to mix in the local community, but in the past month, there have been several violent attacks on them.
One Iranian refugee was permanently blinded in one eye in one incident.
A letter was also circulated threatening the refugees and calling for them not to take jobs or fraternise with Nauruan women and to stop wandering around the island.
Nauru's police chief, Corey Caleb, has refused requests to say what action, if any, has been taken.