Armed rebels took control of all 196 bodies recovered from the Malaysia Airlines crash site and had them loaded on Sunday onto refrigerated train cars bound for a rebel-held city, Ukrainian officials and monitors said.

The surprising, rapid-fire developments on Sunday morning came after a wave of international outrage over how the bodies of plane crash 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.

Meanwhile, a separatist rebel leader said on Sunday that they have recovered the black boxes from the downed plane and will hand them over to the International Civil Aviation Organization.

Alexander Borodai also said the bodies recovered from the crash site would remain in refrigerated train cars at a station in the rebel-held town of Torez until the arrival of an international aviation delegation.

A spokesman for Ukraine's Security Council said the rebels were doing all they could to hide evidence that Russian missiles shot down the airliner.

Ukraine and the separatists accuse each other of firing a surface-to-air missile on Thursday at Flight MH17 as it flew from Amsterdam to Kuala Lumpur 10,000 meters above the battlefields of eastern Ukraine. Both deny shooting down the plane. All those onboard the flight - 283 passengers and 15 crew - were killed.

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 an SA-11 surface-to-air missile from separatist-controlled territory in eastern Ukraine."

US Secretary of State John Kerry said on Sunday that evidence points to separatists in Ukraine using a missile system that came from Russia.

"It's pretty clear that this is a system that was transferred from Russia," Kerry said in an interview on CNN.

But top Russian officials and Moscow's state media have suggested that the new Kiev leaders staged the attack to blame the rebels and convince their Western allies to deploy troops and help seal Ukraine's porous border with its giant eastern neighbor.

AP-Reuters