International monitors said yesterday they has been allowed to visit more of the site where a Malaysian airliner crashed in rebel-held eastern Ukraine, though gunmen still stopped them approaching some of the wreckage.

In sometimes tense scenes with pro-Russian rebels clearly uncomfortable at having observers and the press at the scene, a top official at the Organisation for Security and Cooperation in Europe said access had improved since they arrived on Friday.

“We have now had the possibility to see a bit more of this rather large scene. We have observed the situation here as it was presented to us. We also had the possibility to speak to those who are in charge here, and to speak to inhabitants of a local village,” said Alexander Hug, deputy chief monitor of the OSCE special monitoring mission to Ukraine.

“As in any job, the coopera-tion improves over time and we had better access today,” he told reporters.

On Friday, a group of monitors were hampered in their work by “armed personnel who acted in a very impolite and unprofessional manner. Some of them even looked slightly intoxicated,” an OSCE spokesman said.

Yesterday, gunmen formed a line to separate the observers from parts of the fields where the plane crashed, killing all 298 people on board.

World leaders have called for a rapid investigation into Thursday’s airliner disaster, which could mark a pivotal moment in deteriorating relations between Russia and the West. The United States and other powers said a surface-to-air missile appeared to have been fired from rebel-held territory.

Some officials fear that the crash site may have already been compromised

Ukraine has said Russia played a decisive role in shooting down the plane, and called on Moscow to hand over what it said was the Russian crew of the SA-11 radar-guided missile system.

The pro-Russian rebels, however, say they have not touched the site and blame the Ukrainian authorities for not allowing other experts access to the site.

At one point yesterday, a Reuters correspondent heard a senior rebel tell the OSCE delegation they could not approach the wreckage and would simply be informed in due course of an investigation conducted bythe separatists.

Organisation for Security and Cooperation in Europe monitors speak with a pro-Russian separatist, left, at the crash site of Malaysia Airlines Flight MH17, near the settlement of Grabovo in the Donetsk region yesterday. Photo: Reuters

Fighters later let them visit an area where one of the Boeing 777’s two engines lay.

Ukrainian President Petro Poroshenko condemned the interference with work at the crash site, saying he would not tolerate behaviour that threatened an objective investigation.

“We will not tolerate interference with the work of the commission,” he said.

Some officials fear that the crash site may have already been compromised.

Locals wandered over a part of the crash site on the outskirts of the village of Rozsypne, leaving flowers and toys on the wreckage. A Reuters witness saw that some of the debris had been moved since Friday.

The rebels called for help from Moscow to recover bodies starting to rot after two days in baking summer heat.

“There’s a grandmother. A body landed right in her bed. She says ‘please take this body away’. But we cannot tamper with the site,” rebel leader Aleksander Borodai said.

“Bodies of innocent people are lying out in the heat. We reserve the right, if the delay continues, to begin the process of taking away the bodies. We ask the Russian Federation to help us with this problem and send their experts.