The search for the doomed MH370 flight has been narrowed after new satellite data excluded much of the vast search area, authorities in Malaysia have said.
Malaysia's acting transport minister Hishammuddin Hussein told a press conference in Kuala Lumpur that the search has been called off in the northern part of the Southern Corridor and is now focused on 469,407 square nautical miles, compared with a previous massive area of 2.24million square nautical miles.
And he defended his government's much-criticised treatment of the victims' relatives, who were told by text message that their loved ones were dead, saying the information was "released out of a commitment to openness and respect for the relatives".
Hussein told the press conference: "As the search for MH370 continues, we remain focused on narrowing the search area. With such strong co-operation from our international partners, the challenge is no longer diplomatic - it is now primarily technical and logistical."
He told the press conference that sometime between 00.11UTC and 01.15 UTC, the aircraft was no longer able to communicate with the ground station.
Hussein said the timescale was consistent with the "maximum endurance" of the aircraft.
"The new analysis I have described was convincing enough for the AAIB to brief the prime minister that MH370 flew along the Southern Corridor and that its last position was in the middle of the Indian Ocean west of Perth," he said.
"Within a few hours the families had been informed and the prime minister announced the new development to the world.
"This type of analysis has never been done in an investigation of this sort.
"There remains more work to be done and we are grateful to Inmarsat, AAIB and the International Investigation Team for continuing to work with the Malaysian authorities.
"This is a developing situation and, as soon as we know more, we will share it."
He said the search and rescue operation in the Northern Corridor had been called off, as well as in the northern part of the Southern Corridor.
"All search efforts are now focused in the southern part of the Southern Corridor in an area covering some 469,407 square nautical miles," he said, adding that they were working to further narrow the search area.
Explaining how the AAIB and Inmarsat had helped pinpoint the aircraft's last known location using a technique that had never been used before, he said experts used the "doppler effect" - similar to the sound of a car changing as it passes by - to help work out an arc of possible positions the plane was in, looking at the frequency a ground station expected to receive and one that was actually received.
To check the theory, they compared it to six other Boeing 777s, he said.
No flights from Perth to the search area have taken place today due to bad weather, he said.
He said a US navy black box locator will arrive in Perth tomorrow, and is due to be fitted in to an Australian ship which is due to dock into Perth on March 28.
He added: "Although yesterday's news was incredibly hard for the family members, it was released out of a commitment to openness and respect for the relatives - two principles which have guided us in our
Malaysia Airlines has been forced to defend the way it handled yesterday's announcement, amid claims that some families received the "heartbreaking" news via text message.
Angry relatives of the lost passengers also accused the airline of withholding information and protests broke out in Beijing as relatives of the Chinese passengers clashed with police outside the Malaysian Embassy.
Australian Prime Minister Tony Abbott has promised assistance for the families of the lost passengers and crew, with visa fees being waived.
Prime Minister David Cameron offered his sympathy over the missing flight as he held talks with Chinese President Xi Jinping.