Local rescue officials estimated there could have been "up to 200" passengers on the boat which was bound for Australia, while a survivor said some 250 had boarded the vessel.

"The 157 rescued have been taken to an immigration centre, where they have been given food and water," head of the rescue operation Rochmali, who only goes by one name, told.

"We have to do proper checks, but they say they're from Iraq, Iran and Sri Lanka," he said, adding that one child was among the three dead.

Police said that the three dead were two children and one woman.

Indonesia's rescue agency was alerted to the incident by Australian authorities on Tuesday evening, Rochmali said.

The boat sank in heavy seas off the fishing town of Cidaun in western Java, from where rescuers set out in their own boats and in vessels lent by the police and fishermen.

An AFP reporter who spoke to survivors said a group of 38, including women and children, had swum for between two and three hours in high seas to reach the shore on Tuesday night.

Their boat was headed for Australia's Christmas Island, which is closer to Java than mainland Australia, when it began taking on water, 42-year-old Sri Lankan survivor Obijet Roy told.