Twenty-seven people have died and dozens may be missing after heavy waves smashed their timber boat onto rocks on Christmas Island in the Indian Ocean off Australia.
Television footage showed the boat rammed bow first onto the rocks, splintering and sinking.
Its asylum seeker passengers, including women and children, were thrown by waves against razor-sharp rocks.
Australian Treasurer and Deputy Prime Minister Wayne Swan said 27 bodies had been recovered and 42 rescued, but warned the toll could rise.
'We don't know how many people were on the boat,' Mr Swan told Australia's ABC television.
Australia's Flying Doctors service said the death toll could be around 50, after the boat was destroyed around 6am local time.
'We threw ropes over the cliffs and we must have thrown in a couple of hundred life jackets. About 15 or 20 people managed to get into the jackets but there are bodies all over the water,' one Christmas Island resident, who wanted to remain anonymous, told the West Australian newspaper.
'There are dead babies, dead women and dead children in the water.'
Australian Prime Minister Julia Gillard said she would return from Christmas leave to ensure she is fully briefed on the rescue operation.
A survivor told Australian police there were some 70 to 80 people onboard the vessel, which appeared to be Indonesian.
Police said they believed most passengers were Iraqis.
Christmas Island, south of Indonesia, is a regular destination for refugee boats, and is home to Australia's main offshore immigration detention centre.
Rescuers said the stormy seas and Christmas Island's jagged coastline made rescuing the asylum seekers very difficult as the island has no totally protected harbour in which to land people.
