GRABOVE: Anger deepened around the world Friday with the United States demanding an “unimpeded” international inquiry after a Malaysian passenger jet was apparently shot down by a missile strike in separatist-controlled eastern Ukraine, killing all 298 on board.

The Malaysia Airlines Boeing 777 came down in a cornfield in the strife-torn region on Thursday, leaving a horrific trail of carnage on the ground, with the United States claiming it was shot down in a missile attack.

Kiev accused pro-Russian separatists battling Ukrainian forces of the “terrorist act” as stunned world leaders called for a full investigation into the disaster, which could further fan the flames of the worst East-West crisis since the Cold War.

The White House response to the tragedy was a clear rebuttal to Russian President Vladimir Putin's charge that Ukraine's crackdown on separatist rebels stoked tensions that led to the crash.

“While we do not yet have all the facts, we do know that this incident occurred in the context of a crisis in Ukraine that is fuelled by Russian support for the separatists, including through arms, material, and training, “the White House said in a statement.

News of the crash sent European, US and Asian stock markets tumbling.

Shares in Malaysia Airlines plummeted almost 18 per cent on Friday morning.

The downing of Malaysia Airlines Flight MH17, enroute from Amsterdam to Kuala Lumpur, heaps new distress on Malaysia and its flag carrier, which is still afflicted by the trauma and global stigma of flight MH370's disappearance four months ago.

The father of one MH17 stewardess wept as he expressed the vain hope that his daughter could be alive.

“We are just hoping she survived even though we know many are dead... We pray that somehow she is safe and comes home,” Salleh Samsudin, 54, said of 31-year-old Nur Shazana Salleh on Malaysian television.

One devastated relative told how her sister Ninik Yuriani, 56 — of Indonesian descent but a Dutch national — was on her way to Jakarta to celebrate the Muslim festival Eid.

“My family is now gathered at my sister's house in Jakarta. We've decided to keep this from my mother. She's so old and weak, I don't think she could take it,” Enny Nuraheni, 54, told AFP.

International fury

Dozens of mutilated corpses and body parts were strewn around the smouldering wreckage in the village of Grabove, near the Russian border.

Shocked residents of the village said the crash felt “like an earthquake”.

Malaysia Airlines said 283 passengers and 15 crew were aboard the plane — including 154 Dutch nationals, 43 Malaysians, 28 Australians and 12 Indonesians.

As many as 100 of those killed were delegates heading to Australia for a global AIDS conference, the Sydney Morning Herald reported.

President Barack Obama warned evidence among scattered debris must not be tampered with as the United States called for a prompt investigation.

The UN Security Council called an emergency session on Friday to discuss the disaster.

Singapore's foreign ministry also demanded a “full and transparent investigation” in a statement Friday.

In a strongly-worded television address Indonesian President Susilo Bambang Yudhoyono said if the plane had been shot down by military weapons “this is a violation of international law and even the laws of war”.

Comments attributed to a pro-Russia rebel chief suggested his men may have downed Malaysia Airlines flight MH17 by mistake, believing it was a Ukrainian army transport plane.

In air tragedy, lightning strikes twice for Malaysia

However Russian President Vladimir Putin's said Kiev bore full responsibility for the crash.

It comes just months after Malaysia's Flight MH370 disappeared on March 8 with 239 on board. That plane diverted from its Kuala Lumpur to Beijing flight path and its fate remains a mystery despite a massive multinational aerial and underwater search.

“This is a tragic day, in what has already been a tragic year, for Malaysia,” Malaysia's Prime Minister Najib Razak told a press conference early Friday after announcing an “immediate investigation”.

Najib added that a team of disaster response specialists had been dispatched to Kiev and that authorities in Ukraine had agreed to try to establish “a humanitarian corridor to the crash site”.

'Blown out of the sky'

In calls with pro-Western Ukrainian President Petro Poroshenko and Dutch Prime Minister Mark Rutte, Obama put down an early marker on the necessary conditions for an air accident investigation.

The White House said that Obama told Rutte the United States was prepared to contribute “immediate assistance” for “a prompt, full, credible and unimpeded international investigation. “Two US officials told AFP that intelligence analysts were reviewing the data to see whether the missile used to down the aircraft was launched by pro-Moscow separatists, Russian troops across the border or Ukrainian government forces.

“We are working through all the analysis,” said one official, adding that there was little doubt that the plane was struck by a surface-to-air missile.

In Detroit, US Vice President Joe Biden said the plane was “apparently... and I say apparently because we don't have all the details yet... shot down. Not an accident. Blown out of the sky. “Poroshenko's spokesman said he believed pro-Russian insurgents downed the jet in the crisis-torn country, where fighting between separatists and the Western-backed government has claimed over 600 lives.

“This incident is not a catastrophe. It is a terrorist act,” the spokesman, Svyatoslav Tsegolko, said on Twitter.

A flurry of comments on social media by rebel chiefs claiming they had shot down a Ukrainian army plane in the exact spot the Malaysian plane went down were hastily removed as they appeared to realise their error.

Alexander Borodai, prime minister of the self-proclaimed “Donetsk People's Republic”, meanwhile told AFP that separatist forces would be ready to commit to a truce for several days to allow full access to the site.

The shooting down of civilian aircraft is extremely rare, and if proved the case, the downing of the MH17 would be one of the deadliest yet.