At least 217 people were still missing after boat sank off the coast of east Java in Indonesia, authorities said [Reuters]

Indonesian rescuers have found 15 people alive about 100km from where a boat capsized, raising hopes of more survivors among more than 200 missing asylum seekers who were en route to Australia.

"Thirteen people were found alive but in weak condition. Rescuers found them in a dinghy in the waters off the island Nusa Barong and took them to shore," Kelik Purwanto, Trenggalek district search and rescue official, told the AFP news agency on Monday.

Two Indonesian men were found on Monday afternoon on Sendang Biru beach near eastern Java's Malang city and are suspected to be crew members who abandoned the sinking ship.

"But we cannot confirm that just yet," East Java provincial Disaster Management Agency chief Siswanto told AFP.

Rescuers had held out little hope of finding more survivors in bad weather and high seas, calling it the "largest loss of life" yet from the sinking of one of the many boats packed with Asian and Middle Eastern migrants who undertake the perilous sea voyage from Indonesia to Australia.

Five rescue boats and two helicopters, deployed to comb Indonesia's far-eastern shores despite bad weather, were joined by an Australian navy patrol ship and surveillance aircraft, officials said.

"Visibility is really low. Currents are very strong, waves are up to three metres high and it has just started to rain," Purwanto said earlier.

Overloaded boat

The fibreglass vessel had a capacity of 100 passengers but was carrying about 250 migrants, mostly Afghans and Iranians, when it sank on Saturday off Java island.

Police blamed the accident on overloading, telling the country's official news agency Antara that the vessel appeared to have been carrying more than twice its capacity.

Migrants on board also included Pakistanis, Iraqis, Turks and Saudis.

Fishermen plucked 33 survivors six hours after the accident and were taken to Blitar city on Sunday for identification by the International Organization for Migration (IOM), officials said.

The survivors were placed in a hotel at the IOM's expense, Sutoyo, Blitar immigration official, told AFP.

"The IOM will determine the citizenship of the migrants and their motive for getting on the boat."

Survivors interviewed by AFP said they were heading to Australia's remote Christmas Island when their boat was hit by a storm and capsized.

Crew members and migrants had wrestled over 25 life vests on the doomed boat, officials said.

"The migrants said the six crew members had rushed for the life vests, put them on themselves and swam off," Sutrisno, East Java search and rescue agency chief, told AFP.

'Callous disregard'

They said they had paid agents between $2,500 and $5,000 to seek asylum in Australia and claimed their United Nations documentation papers were lost at sea.

Rescuers had held out little hope of finding more survivors in bad weather and high seas [Al Jazeera]

Thousands of asylum-seekers head through Southeast Asian countries on their way to Australia every year and many link up with people-smugglers in Indonesia for the dangerous voyage on ramshackle boats.

Christmas Island is a favoured destination for people-smugglers, lying closer to Indonesia than Australia.

Jason Clare, Australia's home affairs minister, said on Monday that Indonesia had requested help from Australian police to investigate people-smugglers, who he said had showed a "callous disregard for human life".

"The only way to tackle this effectively (is) if you've got police forces in Australia and in Indonesia, police forces across the region working very closely together," he said.

Canberra has suffered numerous setbacks in its attempts to enforce a regional strategy on the problem, including a rebuff in August from Australia's High Court to its plans to institute offshore processing of asylum-seekers.

Last month, a ship carrying about 70 asylum seekers from Afghanistan, Iran and Pakistan capsized off the southern coast of Central Java, killing at least eight people died. Nearly 50 people are believed to have died in wild seas during a shipwreck in the same area in December 2010.

Source: Al Jazeera and agencies