As the search for missing Malaysia flight MH370 resumed on Wednesday morning, a special envoy sent by President Xi Jinping was en route to Kuala Lumpur to press for details about the fate of the vanished airliner, as relatives of passengers accused that country's officials of lying about the flight's final hours.
While weather conditions over the southern Indian Ocean have improved, the crisis over Malaysia Airlines flight 370 raged on, topping the agenda of a central government meeting in Beijing chaired by Premier Li Keqiang .
Xinhua said Deputy Foreign Minister Zhang Yesui would act as the special envoy and head for Kuala Lumpur as soon as possible to "learn about the situation" and "ask the Malaysian side to properly handle related issues".
Watch: Chinese relatives demand 'truth' over MH370 crash
Another deputy foreign minister, Xie Hangsheng , told Malaysia's ambassador to Beijing, Iskandar Sarudin, that China wanted the precise data that prompted Malaysian Prime Minister Najib Razak to announce on Monday night that the flight had "ended" in the southern Indian Ocean.
"We demand the Malaysian side make clear the specific basis on which they come to this judgment," Xie said.
In a statement after the meeting, the State Council said search and rescue was still the priority and that the government would provide legal aid and medical services to passengers' relatives.
After 18 days of anguish, hundreds of Chinese, including relatives of those on board, marched to the Malaysian embassy in Beijing. They carried placards and chanted "liar", and "You owe us an explanation". Tempers flared as protesters pelted the embassy lawn with plastic bottles and scuffled with police, who took no steps to end the demonstration.
Malaysia Airlines chairman Mohammed Nor Mohammed, stuck to his guns, telling a press conference that although no wreckage had been found, there was no doubt the flight was lost.
Acting Transport Minister Hishammuddin Hussein reiterated that British satellite company Inmarsat used a new technique to trace the plane's path over the Indian Ocean.
Using the data, he said the search in a so-called northern corridor had been ended. The remaining search area is now 469,407 square nautical miles.
Air Marshal Mark Binskin, deputy chief of Australia's Defence Force, said the hunt was still monumental. "We are not searching for a needle in a haystack. We are still trying to define where the haystack is," he said.
A dozen aircraft from Australia, the United States, China, Japan and South Korea will scour the seas some 2,500 km (1,550 miles) southwest of Perth in the hunt for potential debris, the Australian Maritime Safety Authority said. Bad weather on Tuesday forced the suspension of the search.
Although officials sharply narrowed the search zone based on the last satellite signals received from the Boeing 777, it was still estimated at 1.6 million square kilometers (622,000 square miles), an area bigger than Texas and Oklahoma combined.
Search teams are racing to find the "black box" data recorders, which could explain why the flight from Kuala Lumpur to Beijing on March 8 changed course before vanishing.
Erik van Sebille, an oceanographer at the University of New South Wales, said the plane could hardly have vanished in a more inhospitable place than the southern Indian Ocean. "It's got some of the strongest winds in the world and the highest waves."
Australia said improved weather would allow the hunt for the plane to resume today after gale-force winds and heavy rain forced a day-long delay.
Chinese media questioned why Malaysian officials had altered the official tally of passengers and crew on Monday.
Najib said 226 passengers and "our 13 friends and colleagues" were aboard, a change from the 227 passengers and 12 crew announced earlier. Malaysian officials said an engineer was previously counted as a passenger.
Danny Lee, Angela Meng, Mandy Zuo, Agence France-Presse, Associated Press
Watch: MH370 relatives in China distraught as hope extinguished