Task force pursuing 'all leads'

Head of recovery effort warns that hunt could 'drag on for a long time'

Even as a vessel equipped with a specialized black-box "pinger" locator raced against the clock to reach the Indian Ocean search area, Australia cautioned on Tuesday that the hunt for the missing Flight MH370 could be long and frustrating.

No wreckage has been found since the Malaysia Airlines jet vanished on March 8, despite an extensive multinational search effort southwest of Perth.