The downing of a Malaysian passenger plane is pushing Russia and the West into deeper confrontation, with Moscow rejecting the growing consensus that pro-Russian rebels shot down the Boeing 777 over eastern Ukraine, and the United States suggesting the Russian military may have played a direct role in the disaster.

U.S. President Barack Obama called the deaths of the 298 passengers "an outrage of unspeakable proportions," and laid blame directly on separatists in eastern Ukraine and their backers in Moscow. The victims included 24-year-old Andrei Anghel, a medical student from Ajax, Ont., en route to a vacation in Bali with his girlfriend.

"Evidence indicates that the plane was shot down by a surface-to-air missile that was launched from an area that is controlled by Russian-backed separatists inside of Ukraine," Mr. Obama said in Washington. "We know that [the separatists] are heavily armed and they are trained, and we know that that's not an accident. That is happening because of Russian support."

Story continues below advertisement

He called on Russian President Vladimir Putin to stop backing the rebels and to allow a full independent investigation into the crash of Flight MH17 on Thursday in a field near the town of Grabovo, about 40 kilometres from the Russian border.

That region of Ukraine is controlled by fighters from the self-declared Donetsk People's Republic, which seeks union with Russia. More than 1,000 people have been killed in four months of fighting between the separatists and the Ukrainian army. In recent weeks, the rebels have used tanks and other advanced military equipment, including anti-aircraft weapons that are said to have come from Moscow.

"We don't have time for propaganda, we don't have time for games, we need to know exactly what happened, and everybody needs to make sure that we're holding accountable those who – who committed this outrage," Mr. Obama said.

Relations between Russia and the West were already at a post-Cold War low, with the White House imposing fresh economic sanctions on Moscow this week over the Kremlin's support for the rebels in eastern Ukraine. Russia and the West backed opposite sides in February when protesters deposed the Kremlin-friendly government of Viktor Yanukovych. A month later, Russia seized and annexed the Crimean Peninsula from Ukraine after a referendum there.

The United Nations Security Council, of which Russia and the United States are permanent members, passed a unanimous resolution on Friday calling for an independent investigation of the crash, and Mr. Putin in a phone call to Malaysian Prime Minister Najib Razak expressed support for a ceasefire in eastern Ukraine.

But he kept to language the Kremlin has used throughout the months-long crisis, effectively calling for the government in Kiev to meet with the rebel leaders – which the Ukrainian government has rejected. Aleksandr Borodai, one of the leaders of the Donetsk People's Republic, told reporters that there would be no ceasefire, and at least 20 people were reported killed when shells fell Friday on the rebel-held city of Lugansk.

Mr. Borodai promised international investigators would have access to the crash site, but monitors from the Organization for Security and Co-operation in Europe (OSCE) who reached the area on Friday said that did not happen.

Story continues below advertisement

"They did not have the freedom of movement that they need to do their job. The crash site is not sealed off," OSCE spokesman Thomas Greminger told Reuters. "In the current circumstances, they were not able to help securing this corridor that would allow access for those that would want to investigate."

Mr. Borodai said a corridor would be opened to allow bodies of the victims to be moved to the government-controlled city of Kharkiv for identification by relatives. "Hundreds of bodies are currently lying in fields. Speaking not in my official capacity, but in my human capacity, this is not right," he said.

The rebels say they have no fear of an investigation, claiming it will show the Ukrainian military, not the separatists, shot down MH17. The rebels say they don't have the weaponry to target a plane flying at more than 30,000 feet.

However, Russia's Itar-Tass news service reported on June 29 that fighters from the Donetsk People's Republic claimed to have taken over an air defence base in eastern Ukraine "equipped with Buk missile defence systems." A Buk launcher was filmed in rebel-held territory near Grabovo on Thursday shortly before the plane crashed there.

On Friday, Ukraine's Interior Ministry posted a video on its website purporting to show a Buk launcher on the back of a truck driving towards the Russian border at 4:50 that morning.

There were conflicting and confusing claims over who has MH17's flight recorders. Mr. Borodai said his fighters recovered most of them, and planned to give them to the OSCE. But later Friday, another rebel spokesman said the black boxes were taken by officials from the Ukrainian government's Ministry of Emergency Services.

Story continues below advertisement

The UN Security Council showed more signs of acrimony than co-operation. U.S. envoy Samantha Power went further than Mr. Obama, suggesting the type of weaponry believed to have been used to shoot down MH17 was so sophisticated that "it is unlikely that the separatists could effectively operate the system without assistance from knowledgeable personnel, thus we cannot rule out technical assistance from Russian personnel in operating the system."

Russia's UN ambassador, Vitaly Churkin, warned against attempts to prejudge the outcome of the MH17 investigation.

Mr. Churkin said the downing of the passenger plane could not be separated from the months-old political crisis in Ukraine and Western support for Kiev's military operations against the separatists in Donetsk and the neighbouring region of Lugansk.

"We place all blame on the Kiev government and call on the Ukrainian side to take measures to stem such incidents in the future," Mr. Churkin told the Security Council. "Kiev chose the wrong path and, their western colleague prodded them – and I'm talking about the U.S., here – and pushed them to escalate the crisis. They are trying to lay the blame for the catastrophe caused by this on Russia."

Mr. Churkin said the Ukrainian government was also culpable for allowing airlines to fly over conflict area. The airspace had been shut below 31,000 feet, but MH17 was flying at an approved 33,000 feet at the time it appears to have been shot down. Eastern Ukraine's airspace is now closed to all non-military traffic.

In a statement Malaysia Airlines said its plane had been flying at 35,000 feet Thursday, but "upon entering Ukrainian airspace, MH17 was instructed by Ukrainian air traffic control to fly at 33,000 feet."

Story continues below advertisement

An emotional Ukrainian Prime Minister Arseniy Yatsenyuk urged the international community to see in the MH17 tragedy proof of how dangerous the war in eastern Ukraine has become.

"This is the crime against humanity. All red lines have been already crossed," he said in televised remarks, pausing to exhale in an apparent attempt to maintain his composure.

"We ask our international partners … to make everything we can to stop this war. A war against Ukraine, a war against Europe, and – after these terrorists shot down a Malaysian aircraft – this is the war against the world. Everyone is to be accountable and responsible. I mean, everyone who supports these terrorists, including the Russian Federation and the Russian regime."