Sydney: Fifty asylum seekers, including children, were feared dead after their boat smashed to pieces in violent seas off Australia as helpless witnesses looked on in horror, medical officials said.
Another 36 were injured, including three critically, in the disaster off Christmas Island, the Royal Flying Doctor Service told AFP on Wednesday.
Residents watched horrified as the tragedy unfolded in front of them, helpless to assist those dashed against the rocks and debris as bodies floated in the churning sea.
"There were children in the water. There was one very small child in a life jacket floating face down for a very long time... clearly dead," local shop owner Simon Prince told Sky News.
"It`s something I`m not going to forget very quickly."
Residents, woken near dawn by the screams of victims, gathered life jackets and rushed to the jagged limestone cliffs to help the victims, but strong winds blew the flotation devices back onshore.
"We could hear the screaming," a tearful Ingrid Avery told Melbourne radio. "Screaming, screaming and I could hear children screaming."
Witness Phillip Stewart said he saw people drowning after their boat broke up as it was pounded by large waves against the jagged cliffs of the remote island off western Australia.
"The tragedy continued for some time and we witnessed people actually drowning," he said.
Naval vessels managed to rescue some from the water, but authorities were not yet able to confirm the number of dead, missing or those who survived the early morning emergency.
Australia`s acting prime minister Wayne Swan fronted the media with Prime Minister Julia Gillard absent on holiday, but he gave few details, saying only that a "tragic incident" involving an illegal boat had occurred in the Indian Ocean off Christmas Island.
Witnesses said the boat was crowded with passengers, mostly families, and a number were lying listless and ill on the deck as it drifted without power and was dashed on the rocks.
"The waves came in and the boat crashed onto the rocks and smashed the boat, and people were drifting around," local councillor Kamar Ismail told AFP.
Ismail said locals had tried their best to pull survivors from the water "but we can`t do much because the sea was very, very rough".
"Once it hit the rocks it shattered into pieces. I heard people screaming for help, we just said to them `We can`t,` we can`t do much, we could throw them life jackets, that`s all."
Video broadcast on local television showed a modest vessel floundering in heavy seas before being smashed on the rocks.
Michael Foster, another of the island`s residents, said the navy was "doing their best" but that the survivors were dangerously close to cliffs.
"Most of the people were right next to the rocks," Foster said. "You could hear the women screaming, it was trying times for people trying to help them."
The nationalities of those on the wooden fishing vessel have not been confirmed but reports said they were mostly Iranians and Iraqis.
Thousands of asylum seekers from Iraq, Afghanistan and Sri Lanka have made their way to Australia this year, often on rickety boats from Indonesia.
Christmas Island, a tiny island in the Indian Ocean and some 2,650 kilometres (1,650 miles) northwest of Perth, has Australia`s main immigration detention centre and is where all asylum seekers arriving by boat are taken.
Refugee and rights advocates have long fought against Australia`s policy of detaining illegal arrivals on the far-flung island while their claims are assessed, saying health and other services are limited and stretched there.
Canberra is pushing for a regional processing centre to be built in East Timor in the hope of deterring refugees from making the perilous sea journey to Australia, which has claimed hundreds of lives in the past decade.
Five Afghan refugees perished last year when their boat exploded off Ashmore Reef, near Christmas Island, injuring 30 others.