The Nauru government says its police are highly capable of handling law and order issues despite threats of violence.
This comes after the appearance of a letter, widely distributed on the island, issuing threats to the refugees there.
The letter claims to be the work of a group calling itself the Youth of the Republic of Nauru but the government says it could be the work of refugee groups or others wanting to disrupt its asylum seeker programme.
Nauru houses more than 1,000 of Australia's asylum seekers and has declared more than 100 of them refugees.
The governnment says there is no evidence to suggest the letter is genuine or the work of any one Nauruan group or individual.
But it says the Nauru police are seeking local help to find those responsible.