Asylum seekers transferred to navy ship

Eighty-one asylum seekers intercepted en route to Australia will be taken to Christmas Island. (AAP)

Eighty-one asylum seekers intercepted en route to Australia will be taken to Christmas Island. (AAP)

Eighty-one asylum seekers who made a distress call have been transferred to a navy ship and will be taken to Christmas Island.

The 81 asylum seekers on a boat that made a distress call en route to Australia have been transferred to a navy ship and will be taken to Christmas Island.

The boat's crew called the Australian Maritime Safety Authority (AMSA) at about 10am (AEST) on Tuesday to request help, while roughly just 40 nautical miles from the Indonesian coast.

Australian and Indonesian authorities launched a major rescue operation but border protection officials found the boat showing "no visible signs of distress".

The navy's HMAS Childers later arrived at the scene and sent a boarding party on to the vessel.

"For safety and operational reasons the people have been transferred to HMAS Childers," AMSA said in a joint statement with Customs and Border Protection.

"Arrangements are being made to transfer them to Christmas Island."

The boat appears to be the latest to call for help shortly after leaving Indonesia, even though it was not in any immediate danger.

A boat carrying up to 180 people appeared to use a similar tactic last week.

Nevertheless, rescuers are on high alert after two boat disasters last month.

A boat carrying about 200 people capsized on its way to Australia on June 21, leaving an estimated 90 people dead. Another boat carrying 134 people sank on June 27, leaving four people dead.

Meanwhile, a suspected asylum-seeker vessel carrying seven people was intercepted northwest of Christmas Island on Tuesday afternoon.

The passengers are now being taken to the island for security, health and identity checks.

And in Sri Lanka, authorities on Tuesday seized two fishing trawlers transporting at least 82 asylum seekers heading to Australia.