The Australian Department of Immigration has released photos of the damage caused by rioters at the detention centre on Nauru on Friday night.
The riot put four people in hospital and caused $A60 million in damage.
A security guard said asylum seekers took over the centre, gained access to a kitchen and armed themselves with knives and steel bars.
An Immigration Department spokeswoman said accommodation blocks which can house 600 people, were burned to the ground. The health centre and the dining room were also destroyed.
Photos were released on Sunday morning.
The Nauruan government said 80% of the detention centre's buildings were destroyed.
The ABC reports there are 545 male detainees at Nauru: 129 have been identified as involved in the riot.
They are being held at the Police watch house. The ringleaders are expected to be charged with affray and property damage.