Traumatised relatives of those aboard missing flight MH370 Friday blasted the Malaysian government for declaring the passengers and crew dead without evidence of the plane's fate, and rejected compensation offers.

Malaysian authorities a day earlier had said they were now classifying the unexplained disappearance of the plane as an "accident" under global aviation conventions and said for the first time that all 239 on board were presumed dead.

But relatives in both Malaysia and China -- two-thirds of the passengers were Chinese nationals -- rejected that declaration.

"We call on Malaysia to withdraw their statement. It lacks a basis in evidence," said Jiang Hui, whose mother was on the plane, calling on authorities to apologise.

More than 100 Chinese relatives of the lost passengers are demanding Malaysia withdraw the statement, according to posts in an online group they use.

In Kuala Lumpur, some 20 relatives held a briefing to blast Malaysia's move and demand answers to a 10-month-old mystery they said has been mishandled from the start and marked by secrecy on the part of the government and flag carrier.

"Almost all families are unanimous in our stand that we do not want to declare our loved ones dead without a shred of evidence," they said in a prepared statement.

"We, the next of kin of MH370, are perplexed as to why the Malaysian authorities are jumping the gun in wanting to make any announcements while the search is a long way from completion."

Family members in Beijing, some of whom burst into tears as they spoke to reporters near a Buddhist temple, said they had received little advance warning of the announcement -- echoing complaints from furious relatives in Kuala Lumpur.

"Malaysia ignored the right of relatives to know the news first," Jiang added.

Malaysia's declaration opens the door for compensation payments, but many relatives told AFP they wanted answers before any compensation.

- 'We want the truth' -

"We don't want money. We want the truth about what happened," said Hu Xiufang, whose only child, daughter-in-law and grandson were on the plane.

Chinese media reported on Friday that the father of an MH370 passenger died suddenly at his home three hours after hearing the plane was missing.

Li Xiaohui, 60, whose son was onboard, had no known serious medical problems at the time of his death, a state-run outlet called The Paper reported.

The plane vanished en route from Kuala Lumpur to Beijing last March 8 in one of history's great aviation mysteries.

Malaysia's government says satellite data indicates the plane inexplicably detoured to the remote southern Indian Ocean, which they suspect was due to "deliberate" action onboard.

But no evidence has turned up despite an ongoing Australian-led search and rescue operation -- the most expensive in history.

The relatives in Kuala Lumpur said they fear Thursday's declaration indicated Malaysian authorities' desire to wash their hands of the affair and leave it unsolved.

They appealed to the governments of Malaysia, Australia and China not to abandon the search.

Chinese relatives have formed a loose-knit group to express their demands, but Beijing is wary of any unofficial organisations and they have met with harassment from police.

Around a dozen policemen on Friday surrounded relatives of MH370 passengers outside the temple, telling them not to speak to reporters and ordering journalists to leave the scene.

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