Nearly 60 asylum seekers have been jailed following a riot at the Nauru immigration detention centre.
Reports also indicate hundreds have escaped the facility.
Explosions, fire and chants of freedoms could be heard coming from the centre from about 5pm (AEST) on Friday, freelance photographer Clint Deidenang reported.
"Sounds of the riot very loud," Mr Deidenang tweeted from the scene.
"I can see rocks fly out from the main entrance."
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"Police seems (sic) to be holding off break out."
He reported hearing seven explosions and billowing smoke from the entrance to the centre.
Within a couple of hours, thousands of local men came to support police, which ignited another potential problem.
"Just heard a loud speaker informing the people at the entrance not to lay hands on the detainees being transported on a bus to the hospital," Mr Deidenang said in a tweet.
He reported that the riot had ended about 9.40pm and that 59 detainees were arrested and taken Nauru jail.
The photographer also tweeted reports others may have escaped the centre.
"Theres (sic) confirmed report(s) of 200 detainees escaped the ... riot. There's also report of unrest at the police station."
News Limited newspapers reported that at least 15 guards and a police officer were injured.
A Nauruan MP took to state television to call for local men to head to the centre and assist police.
There were also reports of staff being taken hostage for a period of time, News Limited reports.
Ian Rintoul from the Refugee Action Coalition said the unrest was not related to Prime Minister Kevin Rudd's announcement on Friday.
Asylum seekers who pay people smugglers to take them by boat to Australia will no longer be allowed to settle here, Mr Rudd said.
His hardline approach means those claiming refugee status will instead be sent to Papua New Guinea for assessment and, if found to be refugees, they will be settled there.
"They have been protesting on Nauru all week," Mr Rintoul told AAP.
He said uncertainty and delays of up to five years processing asylum seekers for possible refugee status had led to Friday's riot.
"It's the delays which are central to their protest."
Mr Rintoul also said Mr Rudd's announcement would only add to their frustration.
An immigration department spokeswoman confirmed that "non-compliant behaviour" had taken place at the centre involving around 150 detainees.
There were also reports of injuries to security staff and detainees who have received medical treatment.
The centre also sustained property damage, the spokeswoman said.
