TRENGGALEK - At least 217 people are missing, and possibly scores more, after an overcrowded boat packed with illegal immigrants heading for Australia sank in heavy seas off the coast of east Java in Indonesia, authorities said on Sunday.

Many of the passengers on the wooden vessel are believed to be economic migrants from countries including Iran, Iraq and Afghanistan. Indonesia is a transit point for illegal immigrants from the Middle East who cross the Indian Ocean in search of a better life in Australia.

Authorities gave differing accounts of the number of people missing and the potential casualty toll.

Sahrul Arifin, head of emergency and logistics at the East Java Disaster Mitigation Centre, said only 76 people of 380 people on board had been rescued.

The boat was wrecked in strong seas about 90 km (55 miles) out to sea on Saturday night, officials said.

"Our search and rescue team have begun sweeping the water around where the accident took place but we are now sending body bags," Arifin said.

However Hariyadi Purnomo, a Search and Rescue (SAR) spokesman in East Java, said 217 remained missing and 33 people had been rescued. SAR site coordinator Kelik Enggar Purwanto told Reuters by telephone those rescued included one woman. Several of the others were boys aged 8-10.

"Survivors are suffering from severe dehydration and exhaustion as they were floating in the middle of the sea approximately for 5 hours," Purwanto said.

No Sign of More Surviors

Purwanto said the boat sank on Saturday morning and had a capacity of about 100 people. He said survivors were found clinging to the wreckage.

"We see no signs of further survivors or casualties and now we're focusing the search east of where the survivors were found yesterday. Based on a statement from the victims, waves hit the side of the boat, breaking it in half and then it capsized," Purwanto said.

"Fishermen found them about 20 miles (30 km) from the shore when the waves were as high as 2 to 3 metres," Purwanto said,  

Philippines TV showed images of more than a dozen shocked survivors huddled in a clinic in Trenggalek, a town on Java's south coast. Immigration officials were interviewing survivors.

"Extreme weather has caused reduced visibility, making the rescue process difficult," Brian Gautama, a SAR member at the site, was quoted as saying by state news agency Antara. "They (survivors) must be evacuated as soon as possible because they can't stay for long in the middle of the sea."

One survivor told authorities four buses with around 60 or more adult passengers each had turned up to the port where they embarked, Antara said, giving no further details.

"The reason for our journey is that I, along with the rest of the people on the boat, wanted to seek asylum in Australia," one Iraqi survivor, who gave his name as Fahmi, told Reuters in Arabic.    

Australian-based refugee advocate Ian Rintoul said the blame for the disaster lay squarely with the Australian government, which had pressured Indonesia into taking a harsh stance against people smuggling.

Earlier this year, Indonesia enacted a new law making people smuggling punishable by a minimum of 5 years in jail, he said.

"What it means is that people come into Indonesia and are desperate to get out of Indonesia as quickly as possible. That happens under the radar. It used to happen much more in the open," Rintoul told Reuters.

Boat people are a major political issue in Australia, although according to U.N. figures the number of asylum seekers reaching Australia is tiny in comparison with other countries.

Australian Prime Julia Gillard has put pressure on Indonesia, where most of the boats leave from, and other neighbours to help stem the number of arrivals.

Australia-based refugee advocate Jack Smit told Reuters the boat appeared to be overloaded. He suggested a new and inexperienced people-smuggling operator trying to make money quickly might be involved.

Indonesia is currently in its wet season, when its waters are prone to storms, making the journey even more hazardous.

Passengers typically pay between $3,000 and $8,000 to get on such a boat, Smit said, which are often ramshackle and poorly equipped for the dangerous voyage to Australia.

The people-smuggling syndicates are often run by people from the Middle East, exploiting family contacts. The sinking off Java is the latest of several such disasters in recent years.