DONETSK, Ukraine: Fighting flared in the eastern Ukrainian city of Donetsk on Monday as investigators began to inspect the bodies of victims of the downing of Malaysia Airlines flight MH17 last week.

Fighting broke out near the railway station at the heart of the rebel stronghold of Donetsk on Monday in what separatists said was an attempt by government forces to seize back the east Ukrainian city.

The government in Kiev denied sending the regular army into the center of Donetsk, which the separatists captured in April, but said small “self-organized” pro-Ukrainian groups were fighting the pro-Russian rebels in the city.

Four people were killed in clashes near the railway station and close to the airport outside Donetsk, local health officials said in the industrial city which was home to about 1 million people before many fled the fighting in the region.

The fighting served as a reminder of the dangers the experts face working in a war zone. International inspectors got access to the remains of hundreds of victims stored in refrigerated railway wagons near the crash site but governments expressed concern over broader access to the rebel-held area.

The government in Kiev denied sending the regular army into the center of Donetsk, which pro-Russian separatists captured in April, but said small “self-organized” pro-Ukrainian groups were fighting the rebels in the city.

Three people were killed in clashes near the railway station and close to the airport outside Donetsk, health officials said.

Artillery fire sent plumes of smoke skywards near the Donetsk railway station, around 60 km from the crash site, in what the separatists said was an attempt by government forces to enter the city they seized in April. The clashes quickly subsided.

Donetsk is at the heart of a rebel uprising against rule by Kiev, and Ukrainian President Petro Poroshenko has vowed to retake the city as part of what Kiev calls its “anti-terrorist operation” against the separatists.

Disaster victims

Against a background of international horror over the fate of the remains of the 298 victims of the Malaysia Airlines disaster, the first international investigators reached eastern Ukraine on Monday.

Dutch forensic investigators told armed separatists guarding train cars full of bodies from the downed Malaysia Airlines jet on Monday that the train must be allowed to leave within hours.

The experts from the Dutch National Forensic Investigations Team — which specializes in victim recovery and identification — also pressed for rebels to seal the train cars parked in the rebel-held town of Torez.

AP journalists at the site said the smell of decay was overwhelming Monday and many with the inspectors wore masks or pressed cloths to the faces on the warm summer day. A train engineer told The Associated Press that a power outage had hit the cars’ refrigeration system overnight and it was not immediately clear why. The cooling system was back up and running early Monday, he said.

The fumbling efforts to recover remains and secure evidence at the crash site have fanned international outrage. Four days after the jetliner was shot out of the sky, international investigators still have had only limited access to the crash site, hindered by pro-Russia fighters who control the verdant territory in eastern Ukraine.

Of the 298 victims killed, 192 were Dutch and another was Dutch-American.

The investigators led by Peter Van Vilet of the Dutch LTFO forensic office climbed aboard to inspect the wagons, surrounded by armed rebels standing nearby.

“I have watched the train and the wagons and i think the story of the bodies is good of quality,” Van Vilet said.

“We got the promise the train is going,” he said, adding he did not know when.

The investigators stood for a moment with heads bowed and hands clasped before ascending the wagon.

Shock turns to anger

US Secretary of State John Kerry laid out what he called overwhelming evidence of Russian complicity in the shooting down of the Malaysia Airlines plane, and expressed disgust at how the bodies of the victims had been treated at the crash site.

“Drunken separatists have been piling bodies into trucks and removing them from the site,” he said on NBC television on Sunday. “What’s happening is really grotesque and it is contrary to everything President Putin and Russia said they would do.” Television images of the rebel-controlled crash sites, where the remains of victims had lain decomposing in fields among their personal belongings, have turned initial shock and sorrow after Thursday’s disaster into anger.

Australian Prime Minister Tony Abbott said he had spoken to Putin for the first time about the disaster. At least 27 Australians were on the flight from Amsterdam to Kuala Lumpur.

Abbott said an Australian investigation team was in Kiev but had been unable to travel to the site. He said there had been some improvement with the Ukrainian government offering access.

“But there’s still a hell of a long way to go before anyone could be satisfied with the way that site is being treated,” Abbott said.