Malaysian officials have stopped looking for missing Malaysia Airlines Flight 370 everywhere except a remote portion of the southern Indian Ocean and have convened an international working group to pinpoint precisely where it went down, the country's acting transportation minister said Tuesday.
Even the Indian Ocean search was on hold Tuesday, however, as rough weather made it impossible to dispatch search aircraft to the region some 1,500 miles west of Perth, Australia. It will be at least Wednesday before the search resumes, Australian officials said.
Authorities cautioned that despite the narrowing the search area, it could still be some time before crews find any sign of the airplane, which vanished March 8 with 239 people aboard.
"We're not searching for a needle in a haystack," Mark Binskin, vice chief of the Australian Defence Force, told reporters. "We're still trying to define where the haystack is."
A day after announcing new analysis of satellite data shows the plane must have crashed into the Indian Ocean, Malaysian officials ended the search along a northern corridor previously suggested as a possible route for the plane.
Acting Malaysian Transportation Minister Hishammuddin Hussein said all efforts are now focused on the southern tip of the southern corridor, an area of between 400,000 and 500,000 square nautical miles, he said.
He said the international working group that will help further narrow the search area involves agencies with "expertise in satellite communications and aircraft performance."
It will build on the existing analysis of satellite data from the British company Inmarsat, which formed the basis for Monday's announcement that the plane could not have made it to a landing strip and must have gone into the ocean.
The analysis led Malaysia Airlines Chairman Md Nor Yusof to tell reporters that "the aircraft is now lost and none of the passengers and crew on board survived."
In Beijing, hundreds of friends and family members of missing passengers marched to the Malaysian Embassy to express their anger and frustration. They claimed they weren't being told the truth by the Malaysian government about what happened to the plane.
"I'm so mad," one upset family member told reporters. He said he felt there was "no evidence" that the passenger jet crashed in the Indian Ocean.
"If you find something: OK, we accept," he said. "But nothing -- just from the data, just from analysis."
Hundreds of uniformed police blocked journalists from joining the protesters as they approached the gates of the embassy. One woman in the crowd, overcome by stress and emotion, was carried to a nearby ambulance on a stretcher.
On Tuesday, in response to the criticism, Hishammuddin said the new analysis technique used by Inmarsat was convincing enough for Britain's Air Accidents Investigation Branch to brief the Prime Minister.
"Within a few hours, the families had been informed, and the Prime Minister announced the new development to the world," Hishammuddin said. "As the Prime Minister stated, this type of analysis has never been done in an investigation of this sort."
He acknowledged the news was hard for the family members to hear. But, he said, "it was released out of a commitment to openness and respect for the relatives, two principles which have guided the investigation."
In addition to the search operation and a police investigation, the Royal Malaysian Air Force is conducting its own inquiry concerning the disappearance of Malaysia Airlines Flight 370, Hishammuddin said.
Malaysian officials, including executives of the state-owned airline, have taken criticism over their handling of the effort.
"We all feel enormous sorrow and pain," Malaysia Airlines Chief Executive Ahmad Jauhari Yahya said Tuesday. "Sorrow that all those who boarded Flight MH370 on Saturday 8th March, will not see their families again. And that those families will now have to live on without those they love."
Asked whether he would resign once his part in the investigation has concluded, Ahmad Jauhari said it was a personal decision that he would make later.
Malaysia Airlines said Tuesday it has offered family members financial support of $5,000 for each passenger aboard the ill-fated flight and was preparing to make additional payments as the prolonged search continues.
But that was little consolation for anguished relatives.
They were still reeling from the devastating news the day before, when a grim-faced Malaysian Prime Minister confirmed their worst fears, announcing Flight 370 went down somewhere in the Indian Ocean.
Then, even as investigators seemed closer than ever to finding traces of the plane, stormy weather forced Australian authorities to call off a day of searching for the Boeing 777.
"It's almost felt like a miniature roller coaster within the day," said James Wood, whose brother Philip was one of three American passengers on the plane.
Families are stuck in a "holding pattern," he told CNN's "AC360."
"We're just waiting and waiting,"
he said, "and not getting any answers one way or another."
The announcement of the plane's fate by authorities has left many key questions unanswered, including what went wrong aboard the Beijing-bound airliner and where its wreckage is located in the deep, wild ocean waters.
Bad weather blocks search
On Tuesday, Hishammuddin said the challenge of the search, which has involved as many as 26 nations, is longer diplomatic but "primarily technical and logistical."
Among the biggest challenges is weather.
When search crews resume their work -- most likely on Wednesday -- they'll be combing the remote area in the southern Indian Ocean where officials now say they believe the flight ended.
"With eight hours of flying to and from the search region, the fleet of P-3 Orion aircraft and other military aircraft have only a precious few hours to scour the search tracks they have been given," Australian Defence Minister David Johnston said.
More than half a million square kilometers (193,000 square miles) have been searched to date, Australian authorities said.
CNN's Kate Bolduan asked Johnston why he was confident that the plane crashed in the ocean.
"I am confident of that because that's the best we've got at this point in time," he replied.
Malaysia Airlines sent a text message to relatives saying "we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those onboard survived."
"They have told us all lives are lost," a missing passenger's relative briefed by the airline in Beijing said.
Reacting to the criticism the airline has come under for informing people by text, CEO Ahmad Jauhari said Tuesday, "Our sole and only motivation last night was to ensure that in the incredibly short amount of time available to us, the families heard the tragic news before the world did."
Prime Minister Najib Razak explained Tuesday that he decided to make his official announcement Monday because he did not want the government to be seen as hiding information on purpose from the families of the missing passengers.
In an address to Parliament in Kuala Lumpur, he said his statement was based on "the most conclusive information we have."