The surprising, rapid-fire developments Sunday morning came after a wave of international outrage over how the bodies of plane crash victims were being handled and fears that the armed rebels were tampering with evidence at the crash site.

Ukraine and the separatists accuse each other of firing a surface-to-air missile at Malaysia Airlines Flight 17 as it flew from Amsterdam to Kuala Lumpur some 33,000 feet (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.

Ukraine says Russia has been sending sophisticated arms to the rebels, which Moscow denies. The crash site is close to the Russian border.

The rebels have been strictly limiting the movements of international monitors and journalists at the crash site, and Ukraine's Emergency Ministry said its workers were laboring under duress and forced to hand over the bodies to the armed rebels.

Associated Press journalists saw reeking bodies baking in the summer heat Saturday, piled into body bags by the side of the road or still sprawled where they landed in the verdant farmland in eastern Ukraine after their plane was shot out of the sky Thursday.

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

It was immediately not clear Sunday if the rebels and the Ukrainian government were working together or at odds with each other on the bodies — and from their comments, many of officials didn't appear to know either.

Nataliya Khuruzhaya, a duty officer at the train station in Torez, 15 kilometers (9 miles) from the crash site, said she saw emergency workers loading plane victims' bodies Sunday morning into five sealed, refrigerated train cars.

She said the train was scheduled to head to the town of Ilovaysk, 35 kilometers (22 miles) further east toward the Russian border, but no instructions had been given about when it would leave or any possible destinations beyond Ilovaysk.

Russian news agencies said the bodies were heading to the rebel stronghold of Donetsk. Ukrainian officials say they expect to have the bodies eventually delivered to government-held city of Kharkiv, but it's unclear if the rebels will agree to do so.

Earlier, Ukrainian Emergency Ministry spokeswoman Nataliya Bystro said recovery workers in the rebel-held territory were forced to give the bodies to the armed gunmen and didn't know where they were going.

"Where they took the bodies — we don't know," Bystro told The Associated Press on Sunday.

Separatists were not immediately available to comment on her statement.

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

"They are armed and we are not," Pilyushny said. "The militiamen came, put the bodies onto the trucks and took them away somewhere."

Neither Bystro nor Pilyushny could explain what happened to the 102 bodies of plane victims that have not yet been recovered.

The U.S. has pointed blame for downing the plane at the separatists, saying Washington believes the jetliner was probably downed by an SA-11 missile from rebel-held territory and "we cannot rule out technical assistance from Russian personnel."

An Associated Press journalist saw a Buk missile launcher in rebel-held territory close to the crash site Thursday just hours before the plane was brought down.

The latest U.S. intelligence assessment suggests that more than one missile system was given to the separatists by the Russians in the last week or so. But both Russia and the rebels vehemently deny any role in downing the plane.

In a blistering article for the Sunday Times, British Prime Minister David Cameron called the attack a "direct result of Russia destabilizing a sovereign state, violating its territorial integrity, backing thuggish militias and training and arming them."

"We must turn this moment of outrage into a moment of action," he wrote.

In a coded rebuke of German Chancellor Angela Merkel and other European leaders who have blocked efforts to impose tougher sanctions on Russian President Vladimir Putin for Russia's actions in Ukraine, Cameron said Europe must now "respond robustly."

"For too long, there has been a reluctance on the part of too many European countries to face up to the implications of what is happening in eastern Ukraine," Cameron wrote.

Despite calls by world leaders for an independent, international investigation into the plane's downing, armed separatists limited observers' access to the crash site for the first few days.

The U.S. State Department described the rebels' refusal to give monitors a full access to the site "an affront to all those who lost loved ones and to the dignity the victims deserve."

Despite the restrictions seen by journalists and observers at the crash site, separatist leader Alexander Borodai insisted Saturday the rebels have not in any way interfered with the work of observers.

The Dutch led the way in outrage over how the victims' bodies were being treated.

"The news we got today of the bodies being dragged around, of the site not being treated properly, has really created a shock in the Netherlands," Dutch Foreign Minister Frans Timmermans told the Ukrainian president in Kiev on Saturday. "People are angry, are furious at what they hear."

Timmermans demanded that the culprits be found.

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

Putin and Merkel agreed Saturday in a phone call that an independent commission led by the International Civil Aviation Organization should be granted swift access to the crash site.