And Ukraine's spy chief said on Saturday that the country has evidence that the missile that downed flight MH17 came from a Russian-operated launcher that has since been moved back to Russian soil.

Michael Bociurkiw, a member of the Organisation for Security and Co-operation in Europe Special Monitoring Mission, said the crash site "looks like a war zone".

On Saturday, armed militants from the separatist-controlled region who were in control of the crash site had granted his team more access than on Friday, when they first arrived and were permitted to stay for only 75 minutes.

"There's a lot of security, people with heavy arms, we are being watched very carefully," Mr Bociurkiw said.

"We are unarmed civilians so we are not in a position to argue heavily with people with heavy arms.

"There are 'experts' here who brought body bags with them. They are moving the bodies to the side of the road – as far as we can tell, no bodies have been moved beyond the crash site. We don't know who they are because we are not allowed, yet, access to them.

"They are going about the business of collecting bodies and body parts, putting them into what looks like professional body bags and bringing them to the side of road."

He had not seen evidence that the flight's data recorders were at the site He had asked to speak to the leader of the group but "they haven't produced any", he said.

The 24-person group from the OSCE is there to observe and collect facts, and share them with the international community.

They are looking at the security of the site, the conditions of the bodies, the status of the debris and personal belongings.

"We are in a very small village and there is quite a surreal atmosphere, you see people trying to get on with their daily lives," Mr Bociurkiw said.

"Right now we are looking at a very, very damaged piece of earth, where it looks like the engines and fuel tanks landed.

"The intensity of the fire was very strong here – bodies and material belongings basically vapourised. It looks like a war zone here."

He was not in a position to conclude whether there had been looting, he said.

There was lots of debris in fairly big pieces that had not been moved.

The debris his team examined was badly burnt and vapourised, but a few hundred metres up the road there was debris that "looks almost like new", he said.

They have found a lot of personal belongings including duty-free bags from Amsterdam airport, and a travel book. He had seen inside some of the body bags which had been left open and the bodies appeared badly damaged, the contents were "very difficult to look at", Mr Bociurkiw said.

Mr Bociurkiw said later he also saw the local miners moving bodies. He said his team had left the site for the day without establishing the identity of the others involved.

“Nobody really knows who they are,” he said.

With every passing day a rigorous investigation was becoming more difficult, he said.

His team was trying to open dialogue with the separatists to allow crash investigation teams from the US, UK and Malaysia to reach the site.

TIME reporter Simon Shuster, reporting from the crash site, said that as soon as the OSCE vehicles left the crash site around 4pm on Saturday (local time) he saw workers beginning to stack bodies onto trucks.

Workers in filthy uniforms stacking corpses from flight #MH17 onto old ZiL trucks. All refusing to say where the dead are being take — Simon Shuster (@shustry) July 19, 2014

Just saw 2 rebel tanks and truck, all loaded up with heavily armed fighters, driving in direction of crash site, passing Shakhtyorsk. #MH17 — Simon Shuster (@shustry) July 19, 2014