Ukraine has accused Russia of helping separatist rebels to destroy evidence after a Malaysia Airlines plane was shot down with 298 people on board.
The government said today that militiamen have removed 38 bodies from the crash site and taken them to the rebel-held city of Donetsk.
It said the bodies were transported with the assistance of specialists with distinct Russian accents.
Ukraine has called on Moscow to insist that the pro-Russia rebels grant international experts the ability to carry out a thorough investigation into the downing of the plane - a demand issued by US President Barack Obama yesterday.
An international delegation visited the crash site between the villages of Rozsypne and Hrabove, about 25 miles from the Russian border, last night but was only allowed to view one small portion. Militiamen behaved aggressively and eventually ordered the team to leave.
At an emergency meeting of the United Nations Security Council, the US laid blame for the crash on the separatists, saying Washington believed the Boeing 777 was likely to have been downed by an SA-11 missile and "we cannot rule out technical assistance from Russian personnel".
Both the White House and the Kremlin called for peace talks in the conflict between Ukrainian government forces and Russian-speaking separatists who seek closer ties to Moscow.
Mr Obama said: "The eyes of the world are on eastern Ukraine and we are going to make sure that the truth is out."
Russian President Vladimir Putin urged that "all sides in the conflict should halt their fighting and enter into peaceful talks".
The dead passengers were from nearly a dozen nations - including holidaymakers, students and a group of renowned experts heading to an Aids conference in Australia - when the plane was shot down while flying from Amsterdam to Kuala Lumpur.
Mr Obama, disclosing that one American was among those killed, called it "a global tragedy".
"An Asian airliner was destroyed in European skies filled with citizens from many countries, so there has to be a credible international investigation into what happened," he said.
In Kiev, Ukrainian Prime Minister Arseniy Yatsenyuk vented his anger in calling for an international investigation.
"We ask all respective governments to support the Ukrainian government to bring to justice all these bastards who committed this international crime," he said.
All sides in the conflict - the Ukrainian government, the pro-Russia rebels they are fighting and the Russian government that Ukraine accuses of supporting the rebels - have denied shooting down the plane. Moscow also denies backing the rebels.
Russian Foreign Minister Sergey Lavrov dismissed accusations that Moscow could be behind the attack.
"Regarding those claims from Kiev that we allegedly did it ourselves: I have not heard a truthful statement from Kiev for months," he said.
At the Security Council, US ambassador Samantha Power said that early on Thursday a journalist saw an SA-11 system - known in Russia as a Buk missile system - in separatist-controlled territory near Snizhne, "and separatists were spotted hours before the incident with an SA-11 SAM system close to the site where the plane came down".
"Separatists initially claimed responsibility for shooting down a military transport plane and claimed responsibility and posted videos that are now being connected to the Malaysian Airlines crash," she said.
"Separatist leaders also boasted on social media about shooting down a plane, but later deleted these messages.
"Because of the technical complexity of the SA-11, 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 systems."
Ms Power said Ukraine also had SA-11 missiles but the United States was not aware of any in the area where the plane was shot down.
She said the downing of the Malaysian airlines jet also followed a pattern of attacks on aircraft by the separatists in June and very recently on Monday and Wednesday.
"If indeed Russian-backed separatists were behind this attack on a civilian airliner, they and their backers would have good reason to cover up evidence of their crime," Ms Power told the council. "Thus it is extremely important than an investigation be commenced immediately."
Russia's UN ambassador, Vitaly Churkin, did not respond to the US allegations but called for an international commission to investigate the crash.
He asked why Ukraine allowed civilian aircraft to fly over an area where military clashes and air strikes were taking place and where anti-aircraft systems were operating, and called on investigators to also determine whether Ukraine met its international obligation to ensure the safety of the flying public and "prevent disasters from occurring".
Ukraine's UN ambassador, Yuriy Sergeyev, reiterated that the downing of the Malaysian airliner would not have happened had Russia not provided the rebels with sophisticated anti-aircraft systems.
He said intercepted phone conversations between rebel leaders and a Russian military intelligence colonel "confirms the terrorists are standing behind this crime" stressing that immediately after the crash, a rebel military leader boasted on social media of shooting down what he thought was a Ukrainian jet.
Mr Sergeyev said communications and intercepts, photos and videos indicated the rebels had at least two SA-11 systems. He added that detained "terrorists" including two Russian citizens who were going to join the rebels, confessed that the Buk system arrived from Russia.
Ukraine's Interior Ministry released a video purporting to show a truck carrying the Buk missile launcher it said was used to fire on the plane with one of its four missiles apparently missing. The ministry said the video was shot by a police surveillance squad at dawn yesterday as the truck headed towards the Russian border.
There was no way to independently verify the video.