Malaysian Prime Minister Najib Razak says a new analysis of satellite data shows that the missing Malaysia Airlines plane plunged into the southern Indian Ocean, leading to the conclusion that all passengers died.
If confirmed, the news would be a major breakthrough in the unprecedented two-week struggle to find out what happened to Flight 370.
The flight disappeared shortly after takeoff from Kuala Lumpur to Beijing with 239 passengers and crew aboard.
Families of the missing passengers were sent a text message before the media update with the new information.
Meanwhile, Chinese and Australian planes on Monday spotted several objects in an area identified by multiple satellite images as containing possible debris from the missing Malaysian airliner, boosting hopes the frustrating search in the southern Indian Ocean could turn up more clues to the jet's fate.
Australian Prime Minister Tony Abbott said the crew on board an Australian P3 Orion had located two objects in the search zone, the first grey or green and circular, the second orange and rectangular.
An Australian navy supply ship, the HMAS Success, was on the scene Monday night trying to locate and recover the objects, and Malaysia's Defence Minister Hishammuddin Hussein said the vessel could reach them within a few hours or by Tuesday morning.
Separately, the crew aboard one of two Chinese IL-76 aircraft combing the search zone observed two large objects and several smaller ones spread across several square kilometres (miles), Xinhua News Agency reported. At least one of the items _ a white, square-shaped object _ was captured on a camera aboard the plane, Chinese Foreign Ministry spokesman Hong Lei said.
``We are still racing against time,'' Hong said at a ministry briefing. ``As long as there is a glimmer of hope, our search efforts will carry on.''
China has redirected the icebreaker Snow Dragon toward the latest find, and that ship was due to arrive early Tuesday. Six other Chinese ships have been directed toward the search zone along with 20 fishing vessels that have been asked to help, Lei said.
Satellite images and data released by Australia, China and France in recent days have identified possible debris in the area that may be linked to the disappearance of Malaysia Airlines Flight 370 on March 8 with 239 people on board _ two-thirds of whom are Chinese.
The ocean depth in the search area ranges between 1,150 metres (3,770 feet) and 7,000 metres (23,000 feet), and the U.S. Pacific command said it was sending a black box locator in case a debris field is located.
The Towed Pinger Locator, which is pulled behind a vessel at slow speeds, has highly sensitive listening capability so that if the wreck site is located, it can hear the black box ``pinger'' down to a depth of about 20,000 feet (6,100 metres), Cmdr. Chris Budde, a U.S. Seventh Fleet operations officer, said in a statement.
``This movement is simply a prudent effort to preposition equipment and trained personnel closer to the search area so that if debris is found we will be able to respond as quickly as possible since the battery life of the black box's pinger is limited,'' Budde said.
The southern Indian Ocean is thought to be a potential area to find the jet because Malaysian authorities have said pings sent by the Boeing 777-200 for several hours after it disappeared indicated that the plane ended up in one of two huge arcs: a northern corridor stretching from Malaysia to Central Asia, or a southern corridor that stretches toward Antarctica.
Malaysian authorities have not ruled out any possible explanation for what happened to the jet, but have said the evidence so far suggests it was deliberately turned back across Malaysia to the Strait of Malacca, with its communications systems disabled. They are unsure what happened next.
Authorities are considering the possibilities of hijacking, sabotage, terrorism or issues related to the mental health of the pilots or someone else on board.