A team of US investigators has arrived on the Indonesian island of Sulawesi to take part in a search for a plane which disappeared without trace on Monday.
The wait for news has been agonising for relatives
The six-man team, including two representatives from the plane's manufacturer Boeing, will investigate causes of the accident.
The search for the Boeing 737-400 was widened on Friday, as there has still been no sign of the wreckage.
A total of 102 people were on board the plane, which was operated by Adam Air.
Rescue teams are combing the west of the island for the plane, which vanished off radar screens on Monday.
The search is now focusing on the flight path and the weather in the area at the time, which may have caused it to veer off-course.
The flight was last identified halfway through its flight from Surabaya, on central Java island, to Manado, on the north-east tip of Sulawesi.
The search had previously concentrated on areas in western Sulawesi, where emergency signals from the plane were last received, but has now moved elsewhere.
"It's impossible that it just disappeared," said Indonesian Vice-President Jusuf Kalla. "Even if it takes a month ... we have to keep searching."
Bad weather has hampered the search, as have false leads. Government officials have apologised for erroneously saying earlier this week that the wreckage had been found.
Meanwhile, off the island of Java, another search and rescue operation is continuing, to find victims of a ferry which sank in the area last weekend.
So far, more than 230 people have been rescued alive, but twice that number are still believed to be missing.
President Sushilo Bambang Yudhoyono ordered that the search should carry on, citing cases from the 2004 Asian tsunami where people stayed alive on rafts for up to three weeks.
An inquiry has begun into the causes of the disaster.
One of the investigators involved said initial reports from surviving passengers and crew suggested the ship had not been overloaded, and that bad weather may have contributed to the sinking.
But she said the committee had not yet reached any conclusions and investigators plan to interview the captain of the ship in the coming days.