Refugee boat 'tragedy' on Australian island

Dozens of asylum seekers are feared dead after heavy waves smashed their timber boat onto rocks on Christmas Island in the Indian Ocean sinking the boat and throwing 70 to 80 people into stormy seas.

Video footage showed the boat rammed bow first onto the rocks, splintering and sinking, and its passengers, including women and children, thrown by waves against razor-sharp rocks.

"There are people in the water crying out for help. There's a tragedy unfolding here," Christmas Island Shire president Gordon Thomson said.

Local media reported that 41 people had been rescued, but some 30 were still missing after the boat was destroyed.

Australia's Flying Doctors service said the death toll could be around 50 with "about 33 walking wounded".

Australian Prime Minister Julia Gillard said she would return from Christmas leave to ensure she is fully briefed on the rescue operation.