The search for missing flight MH370 is now focusing on two vast corridors where the plane could possibly have flown. Twenty-six nations have now joined the search, which is in its tenth day.
Malaysian Acting Transport Minister Hishammudin Hussein said on Monday that searches for a Malaysia Airline plane missing since March 8 have begun in a northern and a southern corridor arcing through much of Asia.
He told a press conference that China and Kazakhstan had initiated search and rescue operations for MH370 from Laos to the Caspian Sea on the northern corridor, while Indonesia and Australia were searching a southern corridor stretching southwards from west of Indonesia's Sumatra island into the southern Indian Ocean west of Australia.
Earlier, Australian Prime Minister Tony Abbott said Malaysia had asked forAustralian help with the search.
"He [Malaysian Prime Minister Najib Razak] asked that Australia take responsibility for the search in the southern vector, which the Malaysian authorities now think was one possible flight path for this ill-fated aircraft," Abbott told parliament.
"I agreed that we would do so."
Hishamuddin also said diplomatic notes had been sent to all countries along the northern and southern search corridors, requesting radar and satellite information as well as land, sea and air search operations.
Three French civil aviation experts who were involved in the search for an Air France jet that crashed in the Atlantic in 2009 have also been called in to share their knowledge.
The disappearance of the Malaysia Airline Boeing 777-200ER on March 8 on its flight from Kuala Lumpur to Beijing has baffled investigators.
Malaysian authorities now say they believe the plane, which was carrying 239 people, was deliberately diverted from its course by someone fully conversant with the plane and commercial navigation.
Malaysian police have been investigating the backgrounds of crew, passengers and ground staff for any indications of a possible motive, but have so far found none.
News that the last radio message from the cockpit possibly came after one of the plane's crucial signaling systems - the Aircraft Communications Addressing and Reporting System (ACARS) - was manually disabled has fueled suspicion of hijacking or sabotage.
But the airline's chief executive, Ahmad Jauhari Yahya, told the press conference on Monday that it was unclear when ACARS was disabled, appearing to contradict statements by Malaysian government officials.
The last signal from ACARS was received 12 minutes before the radio message, thought to have been spoken by co-pilot Fariq Abdul Hamid. A further signal should have been transmitted 30 minutes after the last one, but did not come through, according to Ahmad Jauhari.
Electronic signals between the plane and satellites continued to be exchanged for nearly six hours after MH370 flew out of range of Malaysian military radar off the northwest coast. However, the signals did not provide any exact location for the plane, only establishing the broad arc that is the basis of the current search corridors.
tj/rc (AFP, Reuters, AP)