A separatist leader in eastern Ukraine says rebels have recovered the black boxes from Malaysia Airlines Flight 17.

Alexander Borodai said the devices will be handed over to the International Civil Aviation Organisation.

He also said the bodies recovered from the crash site in eastern Ukraine would remain in refrigerated containers at a train station in the town of Torez until the arrival of an international aviation delegation.

The plane was apparently shot down on Thursday over disputed territory, killing 298 passengers and crew.

Ukraine and the separatists accuse each other of firing a surface-to-air missile on Thursday at Malaysia Airlines flight 17 as it flew from Amsterdam to Kuala Lumpur some 33,000ft above the battlefields of eastern Ukraine. Both deny shooting down the plane. All those onboard the flight - 283 passengers and 15 crew - were killed.

It was immediately not clear today if the rebels and the Ukrainian government are working together or are at odds with each other on recovering the bodies - and from their comments, many officials did not appear to know either.

A Ukrainian emergency spokeswoman said the armed rebels had forced emergency workers to hand over all 196 bodies recovered from the crash site and did not tell them where the bodies were going. 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 delayed or even dashed.

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

Mr Borodai said he is expecting a team of 12 Malaysian experts and that he was disappointed at how long they had taken to arrive. He insisted rebels had not interfered with the crash investigation, despite reports to the contrary by international monitors and journalists at the crash site.

The rapid-fire developments today came after a wave of international outrage over how the bodies of victims were being handled and amid fears that the armed rebels who control the territory where the plane came down could be tampering with the evidence.

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

The US embassy in Kiev issued a strong statement today 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 that 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, and Ukraine's Emergency Ministry said its workers were labouring under duress, overseen by the armed rebels.

Associated Press journalists saw bodies baking in the summer heat yesterday, piled into body bags by the side of the road or still sprawled where they landed in the farmland in eastern Ukraine.

By this morning, journalists saw no bodies and no armed rebels at the crash site. Emergency workers were searching the sprawling fields only for body parts.

There was no immediate word on the bodies of the 102 other plane victims, but Michael Bociurkiw, a spokesman for monitors from the Organisation for Security and Co-operation in Europe, said some bodies have likely been 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 vaporized," he told reporters in Kiev, speaking via phone from the crash site.

Alexander Pilyushny, an emergency worker combing the crash site for body parts today, said it took the rebels several hours yesterday 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 loaded plane victims' bodies into five sealed, refrigerated train carriages.

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 trains. Kharkiv is 185 miles north of the crash site.

He said no information was available on when plane parts would be brought to the city and that the priority now was on recovering bodies. He said a mobile lab to handle DNA analysis was being delivered from Dnipropetrovsk.