Angry relatives of missing passengers on Malaysia Airlines flight MH370 weep after hearing the news that the plane plunged into the Indian Ocean at a hotel in Beijing on Monday. Several heartbroken relatives reportedly fainted and were hospitalized. Photo: AFP

Malaysian prime minister Najib Razak announced Monday that the missing Malaysia Airlines flight MH370 ended in the southern Indian Ocean west of Perth, a remote location far from any land.

"It is therefore with deep sadness and regret that I must inform you that, according to this new data, flight MH370 ended in the southern Indian Ocean," Najib told a press conference, citing new satellite information.

Following Malaysia's announcement, China demands Malaysia  provide all information that led to its conclusion that the flight crashed in the southern Indian Ocean, foreign ministry spokesman Hong Lei said. China will keep going with the   search, and hopes other countries will continue too, he said.

China is also summoning Malaysian ambassador to China for explanation.

The sad news was based on what Najib described as unprecedented analysis of satellite data from UK-based satellite operator Inmarsat and the UK's Air Accidents Investigation Branch (AAIB).

"We have been working with the UK company Inmarsat, using satellite data to determine the area on which to focus the search. The investigation is being led by the Malaysian authorities," AAIB spokesperson Sam Bond told the Global Times Monday, adding that no further comment can be made.

Inmarsat told the BBC the new calculation involved crunching far more data, which included what other aircraft were doing at the time. Inmarsat gave the AAIB the new data Sunday, which had to be checked before it could be made public.

Malaysia Airlines had already told relatives of the 239 people on board the flight it believes the plane went down in the Indian Ocean with no survivors.

"Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived," it said in a text message to relatives, the BBC reported.

There will be a press conference Tuesday with further details, said Najib.

Relatives of passengers were called to an emergency briefing at the Beijing hotel where they have been staying since the plane went missing on March 8.

There is mounting frustration among the Chinese public over the still unanswered questions as to why the Beijing-bound plane suddenly took a sharp left turn over the Malaysian peninsula, and whether the tragedy was caused by hijackers, the actions of crew or as a result of some other mid-air disaster.

There were 153 Chinese passengers on the flight.

While no confirmed objects from the plane were found so far, planes from China and Australia spotted potential debris in the southern Indian Ocean during the search Monday.

Two circular and rectangular objects were spotted by an Australian plane, and an Australian navy vessel was attempting to locate the objects as soon as "the next few hours" to see if they are related to missing plane, Malaysia's Acting Transport Minister Hishammuddin Hussein said during a news conference.

The announcement came hours after a Chinese IL-76 plane spotted two relatively big floating objects with many white smaller ones scattered over several kilometers in the search area.

The Australian Maritime Safety Authority (AMSA) was advised of the  objects sighted by the Chinese plane, and "attempts will be made to relocate them," an AMSA spokeswoman said.

Chinese icebreaker Xuelong has already changed its course toward the debris and is expected to reach the area early Tuesday.

The US Pacific Command has ordered the Pacific Fleet to move a black box locator, into the region, according to a US Navy statement released Sunday. The locator can detect a black box to a maximum depth of 6 kilometers.  

The movement was "prudent" said the statement, as the battery life of the black box's pinger is limited to 30 days.

Ten aircraft joined Monday's search for MH370 including civil and military aircraft from Australia, New Zealand, the US, China and Japan although bad weather was threatening the search efforts in the area.

It was forecast that on Tuesday, a cold front will move through the search area from the west, bringing showers, more low cloud and less visibility.

French investigators said Monday it was too soon to consider launching undersea searches for the wreckage of the Malaysia jet.

Zhang Yiwei and agencies contributed to this story