Australian Defence Minister David Johnston said that the search could take more time than expected. He said planes and ships were "flat out" trying to progress the latest "lead".
"I want to confirm that we have at least several days of intense action ahead of us," he said, adding that "it's very challenging." The detection of sonic pings by defence vessel Ocean Shield in southern Indian Ocean consistent with those emitted by aircraft black box recorders had raised hopes of searchers.
Finding the black box is crucial to know what happened on March 8 before the Beijing-bound Malaysia Airlines Boeing 777 flight MH370 with 239 people, including five Indians, disappeared under mysterious circumstances in midair.
20 sonar bouys, data bouys have been deployed in the search
"We deployed at least 20 sonar bouys, data bouys that indicate the flow of the water. We have a good understanding of where the debris, if there is a debris will have gone to. "We are currently actively and aggressively pursuing where we think that debris field might be so as to give us further information to calculate back where the point of entry might have been," Johnston said, adding 133 missions have been completed so far which will go on with the same intensity.
Air Chief Marshal (retd) Angus Houston, the head of the Joint Agency Coordination Centre (JACC) which is leading the search, said the towed pinger was still trying to re-locate the signals and will do so for "several days". On deploying an underwater vessel 'Blue Fin 21', Houston said, "until we stop the pinger search we will not deploy the submersible."
He said Ocean Shield required to be allowed to continue its work trying to find another signal. "If we can get more transmissions we can get a better fix on the ocean floor which will enable a much more narrowly focused visual search for wreckage." He said the search area also required silence and cannot be crowded with other ships dropping things into the water.