Australia and Papua New Guinea have both pledged to investigate violence at a detention centre that left one asylum seeker dead and 77 injured.
Clashes broke out at Australia's immigration detention centre on Manus Island in PNG on Sunday and Monday.
There are conflicting reports on what sparked the violence on Monday night, with reports PNG police fired shots.
Rights groups have called for an urgent and transparent probe, warning Australia it is failing asylum seekers.
Australia sends asylum seekers arriving by boat for detention and processing in offshore camps in Papua New Guinea and the Pacific territory of Nauru.
Conditions in these camps have been strongly criticised by UN agencies and rights groups.
Fences breached
On Sunday, 35 asylum seekers briefly escaped after breaking a fence at the detention centre. The incident reportedly came after detainees were told that they would not be resettled in Australia.
On Monday, another outbreak of violence led to the death of one asylum seeker, with 77 injured. Most of the injured suffered head wounds, while one was shot in the buttocks.
Australian Immigration Minister Scott Morrison said Monday night's violence happened after asylum seekers broke fences at the detention centre, breaching internal and external perimeters.
PNG police 'were reported to have fired shots' on two occasions, but 'there's no suggestion they fired at asylu.