Race to track down signals

Speaking to reporters in Perth on Sunday, head of the multinational search Retired Air Chief Marshal Angus Houston said the signals were consistent with an aircraft black box flight data recorder.

"This is an important and encouraging lead but one which I urge you to treat carefully," he said, warning caution in drawing any conclusions before the signals were verified.

The Chinese ship Haixun 1 had detected a signal lasting for 90 seconds during searches on Saturday. The same ship had on Friday detected a more fleeting signal, Houston said.

He also said corrected satellite data had shifted the focus to the southern area of the search zone, which is where Haixun 1 was sailing.

"HMS Echo and Australian vessel Ocean Shield are also being directed to join Haixun 01 as expeditiously as possible to assist with either discounting or confirming the detections," Houston said, adding that the Ocean Shield would first investigate a separate acoustic signal which it had detected in its own search area.

Australia is coordinating the search effort in the southern Indian Ocean for the Malaysia Airlines Boeing 777 which went missing on March 8 with 239 people on board.

Race against time

Experts analyzing satellite readings believe flight MH370 crashed into the southern Indian Ocean after it lost contact with civilian radar and veered far from its intended Kuala Lumpur-Beijing flight path.

International searchers have been scouring the ocean for signs of debris and the plane's black box flight data and voice recorders ever since.

Black boxes, which provide investigators with vital clues, have beacons which emit sounds so that they can be more easily located, but the batteries in these last for only about a month.

se/crh (AFP, AP, Reuters)