Chinese and Australian ships hunting for a missing Malaysia Airlines jetliner have picked up separate acoustic signals in different parts of a vast Indian Ocean search area and are trying to verify if one could be from the plane's black box recorders.
Australian search authorities said on Sunday a Chinese patrol vessel, the Haixun 01, had picked up a fleeting "ping" signal twice in recent days in waters west of Perth, near where investigators believe Malaysia Airlines Flight MH370 went down on March 8.
ITV News China Correspondent Lucy Watson reports:
More planes and ships were being sent to assist in that area. Meanwhile, Australia's HMAS Ocean Shield had reported a separate "acoustic event" some 300 nautical miles away.
The Ocean Shield is carrying sophisticated US Navy equipment designed to pick up signals sent from the black boxes, which may hold the key to why the aircraft ended up thousands of kilometres off course.
"We are treating each of them seriously. We need to ensure before we leave any of those areas that this does not have any connection with MH370," Retired Air Chief Marshal Angus Houston, head of the Australian agency coordinating the operation, told a media conference in Perth.
A black box detector deployed by the Haixun 01 picked up the signal with a frequency of 37.5kHz per second - the same as emitted by flight recorders - at about 25 degrees south and 101 degrees east, Xinhua reported on Saturday.
Australian search authorities said such a signal would be consistent with a black box, but both they and Xinhua stressed there was no conclusive evidence linking it to the Boeing 777.