Hope is fading for scores of asylum seekers still missing after their boat capsized en route to Australia.
The Australian Maritime Safety Authority says weather conditions are starting to deteriorate, as it intensifies its search for about 90 missing asylum seekers north of Christmas Island.
Efforts to find survivors continued all through Thursday night. Scores are feared dead.
The boat was believed to have been carrying about 200 people. At least 110 people have been rescued so far, but the ABC reports scores are feared dead.
HMAS Wollongong and HMAS Larrakia and three merchant vessels are at the scene, but rough conditions are making it hard to find survivors. The incident is about 200km north of Christmas Island, in Indonesian waters.
An Australian Customs plane on routine patrol raised the alarm on Thursday after sighting the overturned boat with people clinging to the hull and floating in the water.
Australian Prime Minister Julia Gillard describes the situation as tragic. She has spoken with President Susilo Bambang Yudhoyono about the incident.
Indonesia is in charge of the rescue operation.
It is not yet known why the boat capsized. It may have come from Sri Lanka.
Indonesian authorities confirm they were told on Tuesday a boat in the area was in distress north of Christmas Island.
Whether this was the same boat is being investigated.
Home Affairs Minister Jason Clare said rumours that another vessel was in distress, possibly off the coast of East Timor, were untrue.
"That search and rescue effort has now been called off," he said.
So far this year, 57 asylum seeker boats carrying a total of 4006 passengers and 82 crew have arrived in Australia.
At least 50 asylum seekers died after a boat carrying asylum seekers hit rocks on Christmas Island in December 2010.
Australian government accused
Refugee groups have accused the Australian government of responding too slowly.
They say the tragedy could have been averted, because it was known the boat was in trouble as long ago as Tuesday.
The Australian Maritime Safety Authority, however, says it could not have intervened sooner to assist a boat carrying asylum seekers because it was not in Australian waters.
The Refugee Action Coalition says the Australian government should have responded faster because it had learned the boat was in trouble on Wednesday.
But the Australian Maritime Safety Authority says it was not Australia's decision to make.