Five people are missing and presumed dead as a search was suspended after 106 people were plucked to safety from a sinking asylum-seeker boat off Christmas Island.
The Australian Maritime Safety Authority (AMSA) received a request for help from the stricken vessel 120 nautical miles from the Australian Indian Ocean territory of Christmas Island early in the day.
An alert was sent out and a navy ship and a customs and border protection aircraft responded, along with a merchant ship.
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Just weeks away from an election in Australia in which boatpeople are a divisive issue, rescuers averted a major disaster by pulling 106 people to safety. But five remain missing and feared dead.
"The vessel was upright, but partially submerged. A number of people were sighted in the water," an AMSA spokeswoman said of the scene when the navy ship HMAS Parramatta arrived.
"Information received from survivors indicates that up to five people remain unaccounted for.
"After an extensive search of the area for further survivors or bodies, none have been sighted. It is therefore believed any people unaccounted for have gone down with part of the vessel."
There were no details of the nationalities of those missing, nor whether they were men, women or children.
With darkness approaching, the search was suspended and HMAS Parramatta steamed to Christmas Island.
Survivors face being sent to Papua New Guinea for processing once medical assessments are made.
The latest tragedy came as Australian Foreign Minister Bob Carr and Immigration Minister Tony Burke were in Jakarta for regional talks on people-smuggling.
Among others represented in the Indonesian capital are Afghanistan and Sri Lanka -- the origin countries of many asylum-seekers who arrive in Australia after perilous sea journeys.
However, no delegates from Iran turned up even though it is the country that sends the most asylum-seekers into Australian waters.
Prime Minister Kevin Rudd's Labor party last month unveiled a tough new policy banishing boatpeople arriving in Australia to Papua New Guinea for processing and resettlement.
They will not be allowed into Australia even if found after processing to be genuine refugees.
Abbott has pledged his own crackdown that would see all refugees put on three-year temporary visas and forced into a work-for-welfare programme without rights to family reunion, appeal or permanent residency.
