Updated

Russian President Vladimir Putin lashed out against a chorus of international condemnation Monday over Moscow's role in training and arming the rebels believed to have shot down a Malaysia Airlines passenger plane Thursday, killing all 298 on board.

Putin said Russia was doing everything possible to allow a team of experts from the International Civil Aviation Organization, a U.N. agency, to investigate the scene. He also again criticized the Ukraine authorities in Kiev for reigniting the fighting with the pro-Russian rebels who control the crash site.

"We can say with confidence that if fighting in eastern Ukraine had not been renewed on June 28, this tragedy would not have happened," Putin said. "Nobody should or does have a right to use this tragedy for such mercenary objectives."

That statement came in the wake of comments by the United States on Sunday, presenting what it called "powerful" evidence that the rebels shot down the plane with a Russian surface-to-air missile.

"Russia is supporting these separatists. Russia is arming these separatists. Russia is training these separatists," Secretary of State John Kerry said on CNN's `State of the Union.'

The leaders of Britain, France, Germany and Australia also spoke to Putin by phone late Sunday. European foreign ministers are also meeting in Brussels Tuesday to consider further sanctions on Russia.

In an opinion piece for the Sunday Times, British Prime Minister David Cameron said there was a "growing weight of evidence" suggesting that the rebels shot down the plane.

If that was the case, Cameron said that was "a direct result of Russia destabilizing a sovereign state, violating its territorial integrity, backing thuggish militias and training and arming them."

Meanwhile, The Associated Press reported that 21 more bodies had been discovered at the crash site and had been piled by the side of the road in black body bags. Over the weekend, pro-Russia rebels had transported nearly 200 bodies from the crash site into four refrigerated boxcars in the nearby town of Torez, an act that drew international condemnation and accusations that the site was being tampered with to forestall a full investigation. In addition to the removal of the bodies, the AP reported that cranes had moved pieces of the Boeing 777 from the crash scene.

Australian Prime Minister Tony Abbot, whose country lost 28 citizens in the crash, told a Sydney radio station that the rebels' treatment of the crash site was "completely unacceptable" and "more like a garden cleanup than a forensic investigation."

The United Nations Security Council was set to consider competing resolutions -- one drafted by Australia, the other by Russia --  that would call for a thorough and impartial investigation into the crash. Western diplomats told Fox News that the introduction of a Russian resolution was seen as a delaying tactic by Moscow.

Reuters reported that the final draft of the Australian resolution characterized the incident as the "downing" of the plane as opposed to the "shooting down" of the plane in an apparent attempt to win the support of Russia, one of five permanent members of the Security Council with veto power.

Dutch Prime Minister Mark Rutte, whose country lost 192 citizens on the plane, told a news conference Sunday that repatriating the bodies was his "No. 1 priority."

He said all efforts were aimed at getting the train with the bodies to "territory controlled by Ukraine" and that a Dutch military plane was being sent to Kharkiv to set up a coordination center. On Monday, three Dutch members with Holland's National Forensic Investigations Team arrived in Donetsk to join an Organization for Security and Cooperation in Europe mission.

Michael Bociurkiw, a spokesman for the OSCE, said reports from the group's investigators in Ukraine suggest some bodies were 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 said from the crash site.

Experts said that even if investigators are granted access now, it might be too late.

"Even without any deliberate attempt at a cover-up, the crash site is already compromised in forensic terms," said Keir Giles, an associate fellow at the Chatham House think tank. "A reconstruction of the aircraft fuselage and wings would give a picture on how the missile struck and what kind it was. If any aircraft parts have already been removed ... this compromises the objectivity of the investigation."

Rutte said the Dutch foreign minister was headed to the U.N. to lobby "to further expand the international coalition pushing for quick recovery of the bodies and getting to the bottom of the terrible events on MH17."

In the Netherlands, worshippers at church services prayed for the victims, as anger grew over the rebels' hindering of the investigation.

Silene Fredriksz-Hoogzand, whose son, Bryce, and his girlfriend, Daisy Oehlers, were among those killed, said she was appalled their bodies weren't being handed over.

"Mr. Putin, send my children home," she said, speaking on Sky TV from Amsterdam's Schiphol Airport. "Send them home. Please."

Fox News' Jonathan Wachtel and The Associated Press contributed to this report. 

Click for more from Reuters