Australia's Immigration Department is investigating disturbances at its Christmas Island Detention Center. About 150 Afghan and Sri Lankan migrants have clashed there in recent days, leaving several people hurt. The remote processing facility houses more than 1,000 people while their claims for refugee status are assessed.
Police say rival groups of asylum seekers attacked each other with tree branches, pool cues and broom handles. Thirty-seven needed medical treatment and three were flown to the Western Australian capital, Perth, suffering from broken bones.
Officials say it took staff on Christmas Island about half-an-hour to regain control. Afghan and Sri Lankan inmates have been segregated while authorities investigate the cause of the fights.
Police say those who instigated the violence could face charges.

Australia Investigates Brawl Among Asylum Seekers in Camp

Australian Immigration Minister Chris Evans says frustrations among Sri Lankan detainees may be the cause.
"There hasn't been too many problems but there has been some increased tension I think around the Sri Lankans, in particular being a bit concerned as we have had some people removed back to Sri Lanka - found not to be refugees, and obviously the spotlight on the groups that were intercepted in Indonesia," Evans said. "So I think generally there has been a bit of anxiety among Sri Lankan detainees."
The government plans to expand the Christmas Island facility to accommodate 1,400 inmates. Currently just under 1,000 are housed there.
Refugee advocates say the center is overcrowded and that the unrest, which began Saturday, was the result of the cramped conditions.
This year there has been a sharp increase in the number of people trying to illegally enter Australia by boat.
Many are from Sri Lanka. While some have been taken to Indonesia, most are transferred to Christmas Island, a remote Australian territory 2,600 kilometers northwest of Perth, to have their applications for refugee status processed.
Opposition politicians in Canberra accuse the government of losing control of the borders. Prime Minister Kevin Rudd promises a hard-line approach to criminal gangs that smuggle migrants into the country but says that anyone seeking asylum will be treated humanely.
Canberra accepts about 13,000 refugees every year under official humanitarian programs. Most asylum seekers who arrive by boat are eventually deemed to be in need of protection and are allowed to settle permanently in the country.