Fresh riots at Australia's Christmas Island centre
Australian police have fired tear gas to subdue rioting asylum seekers at the Christmas Island detention centre following days of unrest.
Police reinforcements were flown to the island on Thursday after about 250 detainees set fire to buildings and attacked security staff.
Inmates say they are protesting against living conditions and the time it takes to process their asylum applications.
Some asylum seekers have been reportedly held for 18 months.
Christmas Island, off the north-west coast of Western Australia, is home to more than 2,500 asylum seekers.
The centre is overcrowded following a steady surge of asylum seekers arriving by boat in Australia's northern waters.
More than 6,500 arrived in Australia by boat last year, mostly from Sri Lanka, Afghanistan and Iraq.
Bricks and concrete blocks were thrown by protesters and they destroyed two compounds at the prison-like centre, police said.
The incident was the latest in almost a week of similar riots and break-outs at the facility.
Australian Foreign Minister Kevin Rudd condemned the riots as "completely unacceptable".
"How can you expect our officials to process applications for asylum when that sort of thing is happening?" he said in a televised statement, adding that there would be no relaxation of the rules.
Immigration Minister Chris Bowen said police were firmly back in control at the centre.
"Last night buildings were damaged, fires were lit and there were violent approaches to the Australian Federal Police," he said.
The authorities used tear gas and "beanbag" bullets - which have been described as mini beanbags fired out of a gun-like weapon - to bring the protesters under control.
Mr Bowen said another 70 police were being sent the island to bolster the 118-strong force already there.
The Immigration Department announced this week it had transferred almost 100 asylum seekers from Christmas Island to Darwin, following the continued unrest.
Another 500 asylum seekers may be transferred to Darwin from the island in coming weeks, ABC reported.
Mr Bowen said overcrowding and long delays were contributing to a level of frustration which had contributed "significant and serious" incidents at Christmas Island.
Earlier this month, the government announced it would build a new immigration detention centre in the northern city of Darwin to relieve overcrowding on Christmas Island.
The conservative opposition believes harsher measures must be taken to deter more boats from arriving with more asylum-seekers.
Opposition leader Tony Abbott said the detention system was "in crisis".