GRABOVE, Ukraine: Pro-Russian militiamen in Ukraine loaded almost 200 bodies from downed flight MH17 into refrigerated train wagons on Sunday as an outraged United States pointed the finger of blame directly at Moscow and demanded it ensure full access to the crash site for international investigators.
In what is the most unequivocal statement incriminating Russia, US Secretary of State John Kerry said the missile system used to shoot down the Malaysia Airlines jet was "transferred from Russia in the hands of separatists".
European leaders warned Moscow of further sanctions over the crash while Kiev piled on the pressure by releasing fresh recordings of what it says are intercepted conversations between rebels organising to hide the flight's black boxes from international monitors
Malaysia Airlines flight MH17 was blown out of the sky on Thursday by what is believed to be a surface-to-air missile, killing 298 passengers and crew and dramatically raising the stakes in Ukraine's bloody three-month conflict.
Insurgents said they had in hand material resembling black boxes but promised to give them to "international investigators if they arrive".
They were also holding the bodies in refrigerated train carriages until "the experts arrive", said a rebel chief who explained that fighters had moved scores of bodies "out of respect for the families".
"We couldn't wait any longer because of the heat and also because there are many dogs and wild animals in the zone," said Alexander Borodai, prime minister of the self-proclaimed Donetsk People's Republic.
OSCE spokesman Michael Bociurkiw described the stench at Torez station, where armed separatists were guarding the grisly cargo of corpses, as "almost unbearable".
The bodies, some dismembered and charred, had been left rotting in cornfields amid the mangled plane wreckage at the main crash site in Grabove, with debris spread out for kilometres.
Possessions of the victims were also all over the ground: suitcases torn open, passports, books, children's toys.
Ukrainian deputy prime minister Voldoymyr Groysman said salvage crews on Sunday found 27 more bodies and 20 body parts, with emergency workers in surgical masks seen carrying black body bags.
Fighting continued to rage between government forces and rebels in the east, with 13 people wounded in the last 24 hours just 100 kilometres (60 miles) from Grabove.
And Ukrainian authorities said they could not guarantee the safety of investigators on the ground.
Kerry, whose government has condemned reported evidence-tampering and lax security at the crash site, said the missile system used to down the jet was supplied by Moscow.
"We know with confidence, with confidence that the Ukrainians did not have such a system anywhere near the vicinity at that point in time. So it obviously points a very clear finger at the separatists," Kerry told CNN.
He also slammed as "grotesque" the manner in which "drunken separatist soldiers" were allegedly "unceremoniously piling bodies into trucks, removing both bodies, as well as evidence, from the site".
Australia circulated a draft UN Security Council resolution demanding the rebels give "full and unfettered access" to the crash site, and for all parties to cooperate in the probe.
The suspicion of Russian intentions was also high, with Australian Prime Minister Tony Abbott telling ABC: "My fear is that Russia will say the right thing, but that on the ground interference with the site, interference with investigators, interference with the dignified treatment of bodies will continue."
The leaders of France, Britain and Germany signalled they could ramp up sanctions against Russia as early as Tuesday -- barely a week after the last round of toughened embargoes.
Ukrainian Prime Minister Arseniy Yatsenyuk told a German newspaper that taking a plane down was an operation that would take professionals and not "drunken gorillas".
The Washington Post said Ukraine's counterintelligence chief had photographs and related evidence that three Buk M-1 anti-aircraft missile systems moved from rebel-held territory into Russia less than 12 hours after the crash.
The US embassy confirmed as authentic recordings released by Kiev on Thursday of an intercepted call between an insurgent commander and a Russian intelligence officer as they realised they had shot down a passenger jet.
But top Russian officials and state media have suggested that Kiev's new leaders staged the attack to blame the rebels.
Dutch Prime Minister Mark Rutte -- his shocked nation flying flags at half mast in mourning over 193 lost compatriots -- has urged Putin to "take responsibility" for a credible probe, with investigators from the Netherlands set to arrive in eastern Ukraine.
Relatives wait around world
Relatives in the dozen countries whose citizens were killed pleaded for them to be brought home.
"At this current moment I hope the world can assist the families to bring back the remains," Zulkifli Abdul Rahman, brother-in-law of one of the cabin crew, told AFP in Kuala Lumpur.
The disaster has an added poignancy for Malaysia after the March disappearance of the Kuala Lumpur to Beijing flight MH370 carrying 239 passengers and crew.
In the Netherlands, and Australia -- which lost 28 citizens on flight MH17 -- churchgoers prayed for the dead at memorial services.
Dozens of bouquets of flowers had also been laid at Schiphol airport, where the doomed flight had taken off from.
Putin has denied having any influence over the rebels, who had declared Sunday they would only accede to Western demands over the crash if Kiev agrees to a truce.
Ukrainian President Petro Poroshenko ripped up a shaky ceasefire on July 1 and has refused a new truce until the separatists who rose up against Kiev in the wake of Moscow's controversial annexation of Crimea in March give up their arms.
Poroshenko is pressing world leaders to recognise the militias as a terrorist organisation that should be put on trial at the Hague.
"We see no difference between the events in Ukraine and what happened on September 11 in the United States or the tragedy over Scotland's Lockerbie," Poroshenko said.