US and European leaders have called for international investigators to be given full access to the downed Malaysia Airlines Flight MH17 crash site after rebels in eastern Ukraine took control of the recovered bodies.

Following demands among European leaders for Russian president Vladimir Putin to ensure access to the crash site, US Secretary of State John Kerry told NBC's Meet The Press programme: "There's a stacking up of evidence here, which Russia needs to help account for.

"We are not drawing the final conclusion here. But there is a lot that points at the need for Russia to be responsible."

The key question of who controlled the collection of evidence at the sprawling site in rebel-held territory has dominated the day's developments.

International monitors say armed rebels have limited their access to the crash site and Ukrainian officials said armed rebels took the bodies away from their workers by force.

Ukraine and the separatists have accused each other of firing a surface-to-air missile at Malaysia Airlines Flight MH17 on Thursday as it flew from Amsterdam to Kuala Lumpur some 33,000ft above the battlefields of eastern Ukraine.

Both deny shooting down the plane.

All 298 people on board the flight - 283 passengers and 15 crew - were killed.

A wave of international outrage over how the bodies of the plane crash victims were being handled came amid fears that the armed rebels who control the crash site could be tampering with any potential evidence.

Donetsk rebel leader Alexander Borodai said the bodies recovered from the crash site would remain in refrigerated train cars in the rebel-held town of Torez, nine miles from the crash site, until the arrival of an international aviation delegation.

"The bodies will go nowhere until experts arrive," Mr Borodai said, speaking in the rebel-held city of Donetsk.

He also said the plane's black boxes have been recovered and will be handed over to the International Civil Aviation Organization.

Mr Borodai said he was expecting a team of 12 Malaysian experts and that he was disappointed at how long they had taken to arrive.

He insisted that rebels had not interfered with the crash investigation, despite reports to the contrary by international monitors and journalists at the crash site.

Ukrainian government officials, meanwhile, prepared a disaster crisis centre in the government-held city of Kharkiv, expecting to receive the bodies, but those hopes appeared to have been delayed or even dashed.

Deputy prime minister Volodymyr Groysman said 192 bodies and eight body parts had been loaded onto the railway cars.

The leaders of France, Germany and Britain issued a statement demanding that Mr Putin make sure that pro-Russia separatists in Ukraine give full access to investigators at the Malaysian plane crash site, or risk the ire of Europe.

French president Francois Hollande, German chancellor Angela Merkel and UK Prime Minister David Cameron agreed to demand that Mr Putin should force separatists controlling the site to "finally allow rescuers and investigators to have free and total access to the zone".

A statement from Mr Hollande's office said if Russia fails "to immediately take the needed measures, consequence will be drawn" at an EU foreign ministers meeting on Tuesday.

Ukraine said Russia has been sending sophisticated arms to the rebels, a charge that Moscow denies.

The US embassy in Kiev issued a strong statement pointing to Russian complicity in arming the rebels, saying it has concluded "that Flight MH17 was likely downed by a SA-11 surface-to-air missile from separatist-controlled territory in eastern Ukraine".

It said over the weekend of July 12-13, "Russia sent a convoy of military equipment with up to 150 vehicles, including tanks, armoured personnel carriers, artillery and multiple rockets launchers" to the separatists.

The statement also said Russia was training separatist fighters in south-west Russia, including on air defence systems.

The rebels have been strictly limiting the movements of international monitors and journalists at the crash site, which is near the Russian border.

Journalists reported seeing bodies rotting in the summer heat on Saturday, piled into body bags by the side of the road or still sprawled where they fell in farmland in eastern Ukraine, after their plane was shot out of the sky.

By Sunday morning, journalists saw no bodies and no armed rebels at the crash site. Emergency workers were searching the sprawling fields only for body parts, while heavy machinery was seen moving plane debris.

There was no immediate word on the bodies of the other plane victims, but Michael Bociurkiw, a spokesman for monitors from the Organisation for Security and Cooperation in Europe, said some bodies were likely incinerated without a trace.

"We're looking at the field where the engines have come down. This was the area which was exposed to the most intense heat. We do not see any bodies here. It appears that some have been vaporised," he told reporters from the crash site today.

Alexander Pilyushny, an emergency worker combing the crash site for body parts, told reporters it took the rebels several hours on Saturday to cart away the bodies. He said he and other workers had no choice but to hand them over.

"They are armed, and we are not," Mr Pilyushny said.

Nataliya Khuruzhaya, a duty officer at the train station in Torez, said emergency workers had loaded plane victims' bodies into five sealed, refrigerated train cars.

Vasily Khoma, deputy of governor of the Kharkiv region where Ukraine has set up a crisis centre to handle the disaster, said the Ukrainian state railway company had provided the refrigerated train cars. Kharkiv is 185 miles north of the crash site.

He said no information was available on when aeroplane parts would be brought to the city and that the priority now was body recovery.

Mr Khoma added that a mobile lab to handle DNA analysis was being delivered from Dnipropetrovsk.

Residents in Kharkov have been inundating a special call centre to offer their services as volunteers. Ten hotels in Kharkiv say they will give free rooms for relatives of the victims.

In the Netherlands, worshippers at church services across the country prayed Sunday for the victims of the Ukraine air disaster and their next of kin, as anger built over the rebels' hindering of the investigation.

At the St Vitus church in the central city of Hilversum, Father Julius Dresme summed up the nation's pain.

"It's terrible, and everybody's hearts are bleeding and crying," he said.

Dutch foreign minister Frans Timmermans, speaking in Kiev, demanded that the culprits be found.

"Once we have the proof, we will not stop until the people are brought to justice," he said.