The search area for the missing Malaysia Airlines jetliner has shifted north as experts continue to narrow down the vast area, Australia's lead search authority said on Friday.
Air Chief Marshal Angus Houston, who heads the Perth-based Joint Agency Coordination Centre, said at a press conference that the sub-surface search to detect pings from the plane's black box has also begun.
He said the surface search will continue for some time before underwater search is undertaken.
Up to 10 military plane and four civilian planes are searching an area of 217,000 sq km in fair weather, in the rough seas around 1,600km off Perth.
Mr Houston said Australia is sending a new ship HMAS Perth to assist in the search and it will arrive in the search area in about four days.
Experts believe that the Boeing 777-200ER jet went down in the Indian Ocean there based on its last communications with a satellite.
The search there, which is now in its second week, has yielded nothing so far as all objects retrieved have proved to be unrelated to the MH370 plane that went missing on March 8 enroute to Beijing.
Mr Houston said a lot of debris in the ocean were from other activities, fishing in particular. The search area was being adjusted on a "semi-regular" basis.
"We are moving into an area we've never been before, this groundbreaking work is extraordinary," he said.
"Everybody wants to find the aircraft, no one is holding anything," he said. "We are giving you everything that we have available... Clearly it's important that we all know what's going on."
He also said that under the Convention on International Civil Aviation, investigations into the missing plane were Malaysia's responsibility but Malaysia had asked Australia to lead the search.
Mr Houston however stressed that the JACC was not involved in the criminal investigation into the missing plane. This was being handled by the Malaysian police, which is working with foreign intelligence agencies.
So far, the police have not given any indication of the motives for the plane being deliberately diverted but it is looking into the possibilities of hijacking, terrorism, sabotage, psychological and personal problems of the crew and passengers.
Mr Houston said the Western Australian government will host the families of MH370's 239 passengers and crew when they arrive in Perth after the authorities give the green light.