HANOI, Vietnam - Nearly 40 years after hundreds of thousands of Vietnamese fled the country's Communist regime by boat, a growing number are taking to the water again.

This year alone, 460 Vietnamese men, women, and children have arrived on Australian shores - more than in the last five years combined. The unexpected spike is drawing fresh scrutiny of Hanoi's deteriorating human-rights record, though Vietnam's flagging economy may also explain why migrants have been making the risky journey.

The latest boat carrying Vietnamese cruised into Australia's Christmas Island one morning last month, according to witnesses on the shore. The hull number showed it was a fishing vessel registered in Kien Giang, a southern Vietnamese province more than 1,400 miles from Christmas Island, which is much closer to Indonesia than it is to the Australian mainland.

Details are few

Many Vietnamese who have reached Australia have been held incommunicado. The government doesn't release details about their religion and place of origin within Vietnam, both of which might hint at why they are seeking asylum.

Some Vietnamese reach Australia via Indonesia, following the same route that the far more numerous asylum-seekers from South Asia and the Middle East have blazed for more than a decade. Others set sail from Vietnam, a far longer and riskier journey.

In separate statements, the Australian and Vietnamese governments said the overwhelming majority or all of the arrivals were economic migrants, which would make them ineligible for asylum. Several Vietnamese community activists in Australia and lawyers who have represented asylum-seekers from the Southeast Asian country dispute that categorization or raised questions over the screening process Australia uses.

Those activists and lawyers also raise concerns about what will become of the migrants, saying that while Australia doesn't want to keep them, Vietnam doesn't want to take them back.

Sensitive issue

In a statement, the Vietnamese government said it is "willing to cooperate with concerned parties to resolve this issue."

Asylum-seekers are a sensitive issue for Vietnam because their journeys undermine Communist Party propaganda that all is well in the country. They also hark back to the mass exodus after the Vietnam War.

Those Vietnamese who fled persecution by the victorious Communists in the immediate aftermath of the war triggered a global humanitarian crisis. Their plight resonated with the U.S. and its allies, and they were initially given immediate refugee status. In 1989, they had to prove their cases pursuant to the Geneva Convention, and acceptance rates quickly fell as a result. Nearly 900,000 Vietnamese did make it out by boat or over land, with the United States, Canada, and Australia accepting most of them.

Vietnam remains a one-party state that arrests and hands long prison sentences to government critics, including bloggers and Roman Catholic activists. Human Rights Watch alleges torture in custody is routine. Christian groups have reported on alleged suspicious deaths in custody.

Most independent human-rights activists say that repression has increased over the last two years.