The Indians were among 128 asylum seekers, travelling in three boats, intercepted last week and sent for offshore processing, the Australian Associated Press reported on Monday.
"The first vessel was found on Tuesday carrying 18 people from India, who are being interviewed in Darwin," Operation Sovereign Borders Acting Commander Air Marshall Mark Binskin was quoted as saying.
"The group is expected to be returned to India," he said.
Meanwhile, authorities today intercepted a vessel carrying 80 asylum seekers, amid Abbott's visit to Indonesia that is likely to be dominated by talks on immigration issues.
Abbott's visit comes three days after a boat packed with asylum seekers and bound for Australia sunk in Indonesian waters, killing 29 and leaving dozens more missing.
Indonesia is often used as a transit point by asylum seekers desperate to reach Australia's Christmas Island in hopes of starting a better life.
Thousands board rickety fishing boats every year to make the often deadly journey, which typically crosses about 340 kilometres of open sea.
Abbott is under pressure at home to stem the flood of asylum-seekers as he heads to Indonesia for talks with President Susilo Bambang Yudhoyono.
The latest arrival has been reported at Christmas Island. Christmas Island councillor and union leader Gordon Thomson tweeted that about 80 men, women and children have arrived. Thomson also confirmed that the group arrived on two Navy boats,
Meanwhile, a boat thought to be carrying more than 100 asylum seekers from the Middle East sunk off West Java's Sukabumi district after being hit by high waves. The search continued today for dozens believed missing after 35 survivors were rescued.
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