Sydney  - Criminal charges may follow from a weekend brawl at Australia's Christmas Island detention centre that left three asylum seekers needing to be flown to Perth for hospital treatment, Immigration Minister Chris Evans said Monday.

Afghan and Sri Lankan detainees attacked each other using pool cues and broom handles after tensions boiled over between the ethnic groups.

"We've been working with the detainees for a while on these issues, but the point is people will get anxious if they see people are failing in their asylum claims," he said. "If they are found to be refugees they will be offered our protection, if they are not they will be returned."

Evans promised a thorough police investigation and that criminal charges would be laid against those responsible for the violence.

There are 975 inmates at the centre, which is on Australia's Indian Ocean territory of Christmas Island, who are awaiting adjudication of their asylum claims.

Ian Rintoul, spokesman for the Refugee Action Coalition, said that detainees had complained over their frustration at being held in custody.

"What they say is that there was no particular cause," Rintoul told national broadcaster ABC. "People are angry, people are frustrated. The overcrowded conditions inside simply boiled over."

Prime Minister Kevin Rudd told Parliament that the brawl could prejudice the outcome of some refugee applications.

"If a detainee on Christmas Island has committed a serious offence this will be taken into consideration as part of the assessment as whether or not they are granted a visa," he said.  (dpa)