No sign yet of MH370 in first update of underwater search

Australian authorities released their first update on the latest underwater probe for missing flight MH370 today, saying more than 670 square kilometres (260 square miles) had been searched without success.

The Malaysia Airlines aircraft carrying 239 people vanished en route from Kuala Lumpur to Beijing on March 8 and no sign of the jet has been found despite a massive air and sea search.

The Boeing 777, which is believed to have crashed into the southern Indian Ocean after inexplicably veering off course, is now the subject of a renewed underwater hunt far off western Australia.

The Australian Transport Safety Bureau (ATSB), which is leading the search, said the Malaysian-contracted vessel GO Phoenix was continuing to conduct underwater search operations.

The underwater search began on October 6 and followed a survey to map the seabed. About 127,000 square kilometres of the search zone has been mapped so far.

Sophisticated vehicles attached to the ship by tow cables have been programmed to detect the biggest parts of the aircraft likely to be in one piece, such as engines and fuselage.

"GO Phoenix continues to conduct underwater search operations," the ATSB said.

"At one point, operations were halted in order to recover the deep tow vehicle and rectify a cable connection fault. Operations were quickly recommenced."

GO Phoenix is searching the area considered the most likely final resting place of the plane, based on detailed analysis of the aircraft's satellite communications.

A second ship, the Fugro Discovery, is conducting sea trials and is expected to join the search mid next week in the second most likely area, officials have said.

Australia has been spearheading the hunt for the plane, a dauntingly vast task that has been beset by false leads and initial confusion - to the continued frustration of grieving relatives.