Australia officials say the search for the missing Malaysia Airlines plane has been suspended because of bad weather.
The Australian Maritime Safety Authority (Amsa) said high winds and rain meant planes could not fly safely.
Malaysian PM Najib Razak says satellite data showed the plane ended its journey in remote seas west of Australia.
In Beijing relatives of passengers clashed with police outside Malaysia’s embassy, as China asked to see data on which Malaysia’s conclusion was based.
About 200 relatives marched to the diplomatic mission, with scuffles breaking out as they confronted security personnel.
Malaysia Airlines flight MH370 disappeared on 8 March as it flew from Kuala Lumpur to Beijing. It was carrying a total of 239 people, including 153 Chinese nationals.
A multinational search effort has focused on seas some 2,500km (1,500 miles) to the southwest of the Australian city of Perth.
But in a news conference late on Monday, the Malaysian leader said it had to be concluded “with deep sadness and regret” that according to new data “flight MH370 ended in the southern Indian Ocean”.
Speaking to media on Tuesday, Malaysia Airlines CEO Ahmad Jauhari Yahya said: “We do not know why, we do not know how this terrible tragedy happened.”
But he added: “The announcement made last night and shared with families is the reality that we must now accept.”
Malaysia Airlines Chairman Mohammed Nor Yusof described the situation as “an unprecedented event requiring an unprecedented response”.
“The investigation under way may yet prove to be even longer and more complex than it has been since 8 March,” he said.
“But we will continue to support the families as we have done throughout, and to support the authorities as the search for definitive answers continues.”