Dutch experts called Monday for a full forensic sweep of the site where Malaysia Airlines Flight 17 went down and told armed separatists guarding rail cars full of victims' bodies in a nearby town the train must be allowed to leave as soon as possible.
Four days after the Boeing 777 was shot out of the sky, international investigators still have had only limited access to the crash site, hindered by the pro-Russia fighters who control the verdant territory.
Pressure was growing on Russian President Vladimir Putin — who the US and others say has backed and armed the rebels — to rein in the insurgents and allow a full-scale investigation into the downing of the plane.
Russia has denied backing the separatists.
In Washington, President Barack Obama demanded that international investigators get full access to the crash site and accused the separatists of removing evidence from the site.
"What exactly are they trying to hide?" he asked.
Peter Van Vilet, leader of the Dutch National Forensic Investigations Team visiting Ukraine, said seeing the crash site in the farm fields near the eastern village of Hrabove was an emotional experience that gave him goose bumps despite the heat.
The team — which specializes in victim recovery and identification — observed some victims' remains that had not yet been removed from the crash site and pressed the rebels to seal the refrigerated train cars parked in the rebel-held town of Torez, 15 kilometers (9 miles) away.
At the UN in New York, the Security Council will vote later Monday on an Australia-proposed resolution demanding international access to the crash site and a cease-fire around the area, with diplomats pressuring a reluctant Russia to approve it. Australian Prime Minister Tony Abbott said his country would view a Russian veto of the resolution "very badly," adding that "no reasonable person" could object to its wording.
AP journalists said the smell of decay was overwhelming at the Torez train station Monday and many with the inspectors wore masks or pressed cloths to their faces on the sunny, 84 degree Fahrenheit (29 degrees Celsius) day.
Earlier, a Ukrainian train engineer told The Associated Press that a power outage had hit the cars' refrigeration system for several hours overnight but was back up early Monday.
The investigators the Dutch LTFO forensic office stood for a moment with their heads bowed and hands clasped before climbing aboard to inspect the train cars, surrounded by armed rebels. Of the dead, 192 of the plane's 298 victims were Dutch and another was Dutch-American.
"I think the storage of the bodies is of good of quality," Van Vilet said. "We got the promise the train is going."
However, he said the rebels did not say exactly when the train would leave. The Ukrainian government is hoping it will go to the government-controlled eastern city of Kharkiv, where it has set up a crash crisis center, but the rebels have not confirmed any movement yet.
In Kharkiv, another team of international experts arrived, including 23 Dutch, three Australians, two Germans, two Americans, and one person from the UK.
At the charred crash site itself near the eastern village of Hrabove, emergency workers retrieved 21 more bodies Monday, bringing the total to 272 bodies, Ukrainian Prime Minister Arseniy Yatsenyuk said.
Fighting flared again Monday between the separatists and government troops in the eastern rebel-held city of Donetsk, just 50 kilometers (30 miles) to the west of the crash site. City authorities said battles were taking place near the town's airport. An AP reporter heard several explosions and saw smoke rising from that direction.
Fighting began in mid-April between the government and the Russian-speaking separatists in eastern Ukraine after Russia annexed Ukraine's Crimean Peninsula a month earlier.