Dutch investigators have found more human remains at the crash site of the Malaysia Airlines Boeing shot down over war-torn Ukraine, an official with the separatist authorities in the region said Friday.

However, it was too early to say whether the remains were those of people killed in the downing of flight MH17 or combatants in the fighting that has taken place in the same area between rebels and Ukrainian government forces.

"Human remains have been found by experts from The Netherlands. They will be examined. Meanwhile, the work on removing debris from the plane has been suspended," Ella Karakut, a transport official in the separatist government of the self-declared Donetsk People's Republic, told AFP.

Barriers marked "forbidden area - there could be remains of victims of the MH17 crash here" could be seen at the site in Grabove on Friday, AFP journalists said.

Meanwhile, AFP reported that the remains of the victims from downed flight MH17 might never be fully recovered, the Dutch foreign minister said Saturday, as five more coffins were flown out of Ukraine.

"We cannot say at this moment in any certain way at what moment and even if we can recover the last nine (victims) but we will do everything we can in cooperation with authorities here to make that happen and that work is still possible to do," Bert Koenders told journalists after a ceremony in east Ukraine.

The Netherlands is leading a probe into the downing of the Malaysia Airlines jet on July 17, in which all 298 on board, including 193 Dutch nationals, were killed.

Ukraine and the West say the Boeing 777 was shot down by separatist fighters using a BUK surface-to-air missile supplied by Russia, but Moscow strongly denies the charges, pointing the finger back at Kiev.

So far 289 victims had been identified among body parts recovered from the site, but no wreckage has been retrieved due to safety issues.

Dutch Foreign Minister Bert Koenders was expected to discuss the issue with his Ukrainian counterpart Pavlo Klimkin in Kiev on Saturday.