DHAKA: The search for a Malaysian airliner intensified on Sunday, 22 days after it vanished with 239 people on board, as relatives of Chinese passengers arrived in Malaysia to demand answers about their fate.

Eight ships, the largest number so far - and 10 planes from six countries were sweeping a vast expanse of the Indian Ocean off Australia for wreckage from the Malaysia Airlines Boeing 777.

Hopes of finding physical evidence of a crash have been repeatedly raised by debris sightings, then crushed as the items turned out to be random sea junk such as fishing gear.

As the hunt resumed 1,850 kilometres west of Perth, Australia said its former military chief Angus Houston would head a new unit to help in the search, which involves the militaries of seven nations, Australia, China, Malaysia, Japan, New Zealand, South Korea and the United States.

Australia prime minister Tony Abbott said Houston would lead the new Joint Agency Coordination Centre based in Perth.

Houston will coordinate the often delicate diplomatic contacts between search participants, and ensure families get all the information and help they need.

About two-thirds of those on board were Chinese and their loved ones have complained bitterly about what they see as Malaysia’s secretive and incompetent handling of the search.

Thirty-nine relatives arrived Sunday in Malaysia to push for more answers.

BDST: 1519 HRS, MAR 30, 2014