An Australian navy ship was standing ready on Wednesday to help a boat carrying up to 180 people, presumed to be asylum seekers, authorities said, the third boat to send distress signals in the past three weeks between Indonesia and Australia.
About 90 people died after a boat carrying asylum seekers sank on June 21 and around 120 were rescued after another boat sank in the same area a week later.
Those two incidents prompted Australian Prime Minister Julia Gillard to suspend parliamentary business to debate Australia's laws covering the illegal arrival by boat of people seeking asylum, a subject that generates enormous public interest in Australia.
The issue was also discussed when Gillard met Indonesian President Susilo Bambang Yudhoyono during annual bilateral talks in northern Australia earlier this week. l
People seeking asylum in Australia, many from Afghanistan and the Middle East, often set sail from Indonesia heading for Australia's Indian Ocean territory of Christmas Island in dangerous and overcrowded boats after paying people smugglers.
The numbers trying to reach Australia, however, are small compared with the more than 58,000 people who arrived in Europe by sea in 2011, according to UN figures.
In the latest incident off Australia's northwest coast, the Australian Maritime Safety Authority (AMSA) said it had received information "from multiple sources" that an unidentified vessel requested assistance south of Indonesia's Java island.
It later said the Australian navy ship HMAS Wollongong had located the vessel.
"Due to adverse weather conditions it is not safe for HMAS Wollongong to attempt to board the vessel in order to confirm the nature of the distress," AMSA and Australia's Customs and Border Protection said in a statement.
A merchant vessel was also at the scene and a second navy ship was expected to arrive later on Wednesday, they said.
Jakarta has also sent a C-130 transport and reconnaissance aircraft and a navy ship to the area, Indonesian Search and Rescue spokesman Gagah Prakoso said.
Prakoso said the boat was about 50 nautical miles from Indonesia's Panaitan Strait.