Clashes have broken out between refugees from Sri Lanka and Afghanistan at an Australian immigration detention centre on Christmas Island.
Officials took more than half an hour to break up the fights between about 150 inmates - 40 of whom were injured.
The centre has been struggling to cope with a recent influx of refugees, many arriving by boat from Sri Lanka.
Australia plans to increase the capacity of the centre to more than 2,000 beds to cope with the demand.
Fighting erupted in the men's section of the centre, with Afghan and Sri Lankan refugees using tree branches, pool cues and broom handles to attack each other.
Three people were taken by plane to Perth - 2,600km (1,600 miles) away - for treatment for broken bones. Another 37 people were given medical treatment on the island.
Immigration authorities on Christmas Island are investigating what caused the outbreak of violence, and Afghan and Sri Lankan inmates have been temporarily segregated as a precaution.
Australian Immigration Minister Chris Evans said there had been increased tensions in the camp, particularly among the Sri Lankan refugees after some were ruled not to be genuine asylum seekers and were returned home.
The remote processing facility on Christmas Island houses about 1,000 inmates, who are held in custody while their claims for refugee status are assessed.
There has been a tenfold increase in the number of people arriving at the centre in recent months, many of them picked up as they try to reach Australia by sea.
The BBC's Phil Mercer in Sydney says Australian opposition politicians have accused the government of losing control of the country's borders.
Prime Minister Kevin Rudd has promised to take a hard line approach to people smugglers, but has insisted that anyone seeking asylum would be treated humanely.
Last month, the government said it was adding 800 more beds to the 1,200 already at the centre, to deal with the rise in people coming from Sri Lanka.