Ukraine has accused Russia of helping separatist rebels destroy evidence at the crash site of a Malaysia Airlines plane shot down in rebel-held territory - a charge the rebels deny.
As dozens of victims' bodies lay in bags by the side of the road baking in the summer heat, international monitors at the crash site today said they were still being hampered by heavily armed rebels.
"Some of the body bags are open and the damage to the corpses is very, very bad. It is very difficult to look at," Organisation for Security and Co-operation in Europe (OSCE) spokesman Michael Bociurkiw told reporters in a phone call from the site.
He said the 24-member delegation was given further access to the crash site today but their movements were being limited by the rebels. The site sprawls eight square miles (20 sq km) across sunflower and wheat fields between two villages in eastern Ukraine.
"We have to be very careful with our movements because of all the security," Mr Bociurkiw said. "We are unarmed civilians, so we are not in a position to argue with people with heavy arms."
Flight MH17 from Amsterdam to Kuala Lumpur was carrying 298 people from 13 nations when it was shot down in eastern Ukraine on Thursday, close to the Russian border, an area which has seen months of clashes between government troops and pro-Russia separatists.
At an emergency meeting of the United Nations Security Council, the US pointed the finger at the separatists, saying Washington believes the plane was probably downed by an SA-11 missile and "we cannot rule out technical assistance from Russian personnel".
The government in Kiev said 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.
The rebels are also "seeking large transports to carry away plane fragments to Russia", the Ukrainian government said in a statement today.
In Donetsk, separatist leader Alexander Borodai denied that any bodies had been transferred or that the rebels had in any way interfered with the work of observers.
He said he encouraged the involvement of the international community in assisting with the clean-up before the condition of the bodies worsens significantly.
As emergency workers put some 80 bodies into bags today, Mr Bociurkiw stressed that his team was not at the site to carry out a full-scale investigation.
"We are looking at security on the perimeter of the crash site, looking at the status in the condition of the bodies, the status in the condition of the debris, and also personal belongings," he said.
Ukraine also called on Moscow to insist that the pro-Russia rebels grant international experts the ability to conduct a thorough, impartial investigation into the downing of the plane - echoing a demand that US President Barack Obama issued a day earlier from Washington.
"The integrity of the site has been compromised, and there are indications that vital evidence has not been preserved in place," Malaysian Transport Minister Liow Tiong Lai said at a news conference in Kuala Lumpur.
He called for immediate access for Malaysia's team at the site to retrieve human remains.
Ukraine says it has passed on all information on developments relating to Thursday's downing to its European and US partners.
German Chancellor Angela Merkel and Russian President Vladimir Putin agreed in a phone call today that an independent, international commission led by the International Civil Aviation Organisation should be granted swift access to the crash site, said government spokesman Georg Streiter.
The commission should examine the circumstances of the crash and recover the victims, he said, adding that Mrs Merkel urged Mr Putin to use his influence over the separatists to make that happen.
The location of the airliner's black boxes remains a mystery and the separatist leadership remained adamant today that it had not located them. Mr Bociurkiw also said he had received no information on their whereabouts.
Aviation experts, however, have warned not to expect too much from the flight data and cockpit voice recorders in understanding how the plane was brought down.
The most useful evidence likely to come from the crash scene is whether missile pieces can be found in the trail of debris that came down as the plane exploded, said John Goglia, a US aviation safety expert and former National Transportation Safety Board member.
The operation of the Flight 17 does not appear to be an issue, he said.
Mr Obama called the downing of the plane "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.
Both the White House and the Kremlin have called for peace talks in the conflict between Ukrainian government forces and Russian-speaking separatists who seek closer ties to Moscow. Heavy fighting took place yesterday around Luhansk, less than 60 miles (100km) from the crash site, with 20 civilians reported killed.