PERTH, Australia (AP) — Although it has been slow, difficult and frustrating so far, the search for the missing Malaysia Airlines jet is nowhere near the point of being scaled back, Australia's prime minister said.
The three-week hunt for Flight 370 has turned up no sign of the Boeing 777, which vanished March 8 with 239 people bound for Beijing from Kuala Lumpur. Ten planes and 11 ships found no sign of the missing plane in the search zone in the southern Indian Ocean, about 1,850 kilometers (1,150 miles) west of Australia, officials said.
The search area has evolved as experts analyzed Flight 370's limited radar and satellite data, moving from the seas off Vietnam, to the waters west of Malaysia and Indonesia, and then to several areas west of Australia. The search zone is now 254,000 square kilometers (98,000 square miles), about a 2½-hour flight from Perth.
Malaysia has been criticized for its handling of the search, particularly its communications to the media and the family. In something likely to fuel those concerns, the government changed its account of the final voice transmission from the cockpit.
In a statement late Monday, it said the final words received by ground controllers at 1:19 a.m. on March 8 were "Good night Malaysian three-seven-zero." Earlier the government said the final words were "All right, good night." The statement didn't explain or address the discrepancy. The statement also said investigators were still trying to determine whether the pilot or co-pilot spoke the words.
Items recovered so far were discovered to be flotsam unrelated to the Malaysian plane. Several orange-colored objects spotted by plane Sunday turned out to be fishing equipment.
Those leading the effort remain undaunted, with Prime Minister Tony Abbott saying Monday that officials are "well, well short" of any point where they would scale back the hunt. In fact, he said the intensity and magnitude of operations "is increasing, not decreasing."
"I'm certainly not putting a time limit on it. ... We can keep searching for quite some time to come," Abbott said at RAAF Pearce, the Perth military base coordinating the operation.
"We owe it to the families, we owe it to everyone that travels by air. We owe it to the anxious governments of the countries who had people on that aircraft. We owe it to the wider world which has been transfixed by this mystery for three weeks now," he said.
"If this mystery is solvable, we will solve it," Abbott said.
On Monday, former Australian defense chief Angus Houston began his role of heading the new Joint Agency Coordination Center, which will oversee communication with international agencies involved in the search.
The center said Tuesday's search, using 10 planes and nine ships, would focus on less than half of the search zone, some 120,000 square kilometers (46,000 square miles) west of Perth, with poor weather and low visibility forecast. It did not say how far west of Perth the search would be conducted.
The center corrected an earlier statement that said a smaller zone of 64,975 square kilometers (25,087 square miles) would be searched on Tuesday.
"Yesterday's search revealed nothing that was seen or found that had any connection to the Malaysian aircraft," Houston told Australia's Seven Network television earlier Tuesday.
"If we can find any debris anywhere, that will enable the search to be focused much more precisely and the high technology can then come into play," he added.
Malaysian Prime Minister Najib Razak plans to travel to Perth on Wednesday to see the search operations firsthand.
Abbott called the operation "an extraordinarily difficult exercise."
"We are searching a vast area of ocean and we are working on quite limited information," he said, noting that the best brains in the world and all technological mastery is being applied to the task.
The Ocean Shield, an Australian warship carrying a U.S. device that detects "pings" from the plane's flight recorders, left Perth on Monday evening for the search zone, a three- to four-day trip. The Australian Maritime Safety Authority, which is coordinating the search, said it conducted sea trials to test the equipment.
Investigators are hoping to first find debris floating on the surface that will help them calculate where the plane went into the water.
In Malaysia, several dozen Chinese relatives of Flight 370 passengers visited a Buddhist temple near Kuala Lumpur to pray for their loved ones. They offered incense, bowed their heads in silence and knelt several times during the prayers.
Buddhist nuns handed out prayer beads to them and said: "You are not alone. You have the whole world's love, including Malaysia's."
The family members later expressed their appreciation to the Chinese government and the people of Malaysia and the volunteers who have been assisting them. They bowed in gratitude but said they were still demanding answers.
The comments were seen as a small conciliatory gesture after relatives held an angry protest Sunday at a hotel near Kuala Lumpur, calling on the Malaysian government to apologize for what they called missteps in handling the disaster.
Wong reported from Kuala Lumpur. Associated Press writers Eileen Ng in Kuala Lumpur, Kristen Gelineau in Sydney, and Rod McGuirk in Canberra, Australia, contributed to this report.