AFP/Sydney

Australia moved yesterday to tighten security at its main immigration centre after a riot by 150 asylum-seekers, reportedly wielding pool cues, broomsticks and tree branches, left 37 wounded.

Immigration Minister Chris Evans said security would be increased to prevent a repeat of Saturday’s mass brawl between Afghan and Sri Lankan detainees in the remote Christmas Island centre, far off Australia’s northwest.

Australian Federal Police were investigating the matter, in which three inmates were seriously hurt and flown to Perth for treatment, and would charge those responsible if they could identify them, he said.

“Clearly though, security at the centre will be tightened to ensure we don’t have any incidents like this again,” Evans told parliament yesterday.

The violence followed the arrival of scores more asylum-seekers on rickety people-smuggling boats in recent weeks, and the repatriation of some Sri Lankans after they were found not to be refugees.

Evans said some Sri Lankans had become concerned they would also be sent home and tensions could have arisen because most Afghans held at the centre are ultimately given refugee status and resettled in Australia.

“That may well have been at the heart of some of the tensions in the centre,” Evans told ABC radio earlier.

“But essentially we have had a fight between some detainees which got out of hand and until there is a full police investigation, we are only really speculating as (to) what the real causes were.”

More than 40 boats carrying more than 2,000 asylum-seekers, mostly from Sri Lanka, Afghanistan and Iraq, have arrived in Australian waters this year.

As of yesterday, 1,138 were detained at facilities on Christmas Island, which recently moved to increased its capacity by installing temporary beds in a recreation area and shipping in portable buildings.

Prime Minister Kevin Rudd said inmates who took part in the riot risked being refused residency in Australia.

“If a detainee on Christmas Island has committed a serious offence this will be taken into consideration as part of the assessment as to whether or not they are granted a visa,” he told parliament.

In August, the government was harshly criticised for tough security measures on Christmas Island, including electrified razor-wire fences and caged walkways, when a parliamentary committee called them “excessive and inhumane”.