Australia on Sunday sent planes and ships to investigate signals detected by a Chinese ship in the hunt for a missing Malaysian jet, saying they matched black box beacons and were an "important and encouraging lead".

Angus Houston, the Australian head of the mission, said a second "ping" was also being scrutinized 300 nautical miles away in the Indian Ocean, as the one-month lifespan of batteries powering the beacons loomed.

Two vessels were searching underwater for missing Malaysia Airlines Flight MH370 on Saturday, as air and sea missions failed to find any sign of the plane and the clock ticked on the signal from its black box.

Up to 10 military planes, three civilian jets and 11 ships were set to take part in the protracted search in the southern Indian Ocean for the Boeing 777 which disappeared on March 8 with 239 people onboard.

Australia's Immigration Minister Scott Morrison made an unannounced visit to Cambodia on Friday, raising speculation that Phnom Penh will join Papua New Guinea and Nauru in helping resettle asylum-seekers.

Prime Minister Tony Abbott said talks between Morrison and Cambodian officials represented the countries "staying in touch" as partners against people-smuggling.

China has asked to operate under Australian command when it takes part in a major international military exercise led by the United States later this year, a report said Friday.

Beijing's reported decision comes as Australia leads the arduous Indian Ocean search for missing Malaysia Airlines jet MH370 which was carrying 153 Chinese when it vanished.

A U.S. Navy "black box" detector made its much-anticipated debut in the oceanic hunt for flight MH370 on Friday but Australia's search chief warned it was crunch time with the box's signal set to expire soon.

As the extensive search wore on, Malaysian opposition leader Anwar Ibrahim said he believed the country's long-ruling regime was concealing information on the crisis, saying "the government knows more than us."

Malaysia will not rest until it can give answers to the distraught families of those on board missing Flight MH370, Prime Minister Najib Razak said Thursday, admitting the search was a "gargantuan" challenge.

International efforts to find any sign of the Malaysia Airlines plane which vanished on March 8 have so far failed, but search coordinator Australia says there are no imminent plans to abandon the operation.

A Frenchwoman has become the fourth foreign student to be brutally murdered in the Australian city of Brisbane in almost as many months, police said Wednesday.

The battered and naked body of a 21-year-old woman was found in a park near her apartment after what police called "a brutal attack" in the early hours of Friday morning.

Australia's highest court on Wednesday recognized the existence of a third "non-specific" gender that is neither male nor female, in a landmark ruling campaigners said will help end years of discrimination.

The High Court ruled that not everyone should be forced to identify as a man or woman when dealing with officials, saying some people could legitimately describe themselves as gender neutral.

Malaysia revealed the full radio communications with the pilots of its missing flight Tuesday, but the routine exchanges shed no light on the mystery as an Indian Ocean search for wreckage bore on with no end in sight.

The previously unreleased conversations between MH370's pilots and air traffic controllers had been the subject of much speculation as suspicions have focused on whether one or both of its pilots deliberately diverted the plane on March 8 with 239 people aboard.

Malaysian Prime Minister Najib Razak will travel to an Australian air force base near Perth to observe the multi-nation search for missing flight MH370, his government said on Monday.

Transport and Defense Minister Hishammuddin Hussein said Najib would make the trip on Wednesday.