The boat capsized about 120 nautical miles (around 220 km) north of Christmas Island. Since the tragedy took place within Indonesian waters, the Indonesian navy is leading rescue efforts; Xinhua quoted the AMSA as saying.
West Australian Police Commissioner Karl O’Callaghan said a large number of asylum seekers may have drowned.
The distressed vessel was sighted by Australia’s Border Protection Command Dash-8 surveillance aircraft which monitors the vast area of the Indian Ocean.
Up to 75 asylum seekers were reportedly dead and 40 others are struggling to survive.
Australia’s Border and Customs department told Xinhua that at the time of initial contact, the vessel was upside down, and pilots estimated that there were 40 people clinging to the hull and an unknown number of people in the water.
Speaking from Rio de Janeiro where she is attending the G20 summit, Australian Prime Minister Julia Gillard said it was a very distressing and tragic incident.
“We don’t know the full details yet, but clearly we have lost a number of lives in a very dangerous journey from Indonesia to Australia.”
In February, eight asylum seekers drowned off Malaysia during a suspected attempt to reach Australia. In December 2010, at least 50 people died after a boat carrying asylum seekers hit rocks off Christmas Island.