MH17 crash: Experts identify 173 MH17 victims
Forensics teams from the Netherlands say they have so far positively identified 173 victims of flight MH17, which was shot down over Ukraine.
They say they are unable to use dental records or fingerprints to identify more than 100 remaining victims and will have to rely solely on DNA.
All 298 people on board, most of them from the Netherlands, died in the crash in eastern Ukraine on 17 July.
Fighting near the crash site hampered efforts to collect the victims' bodies.
More than 200 international forensic detectives have spent weeks working to identify remains taken from the scene and flown back to the Netherlands.
Wim Heijnen, of the Dutch Forensic Institute (NFI), said the task of identifying the victims was now becoming more difficult and could take several more weeks or months.
Many of the DNA samples gathered at the site, Mr Heijnen said, do not correspond to the victims and could be from rescue workers.
Some remains were badly burned, he added, making it harder to get positive samples.
"I think that the fact we have gotten DNA profiles in quite a short time from three-quarters of the remains is good. But I am, of course, not satisfied," he told reporters in The Hague.
"We want more DNA profiles from remains and we will carry on to get them. It becomes, understandably, more difficult and sadly more time consuming to do that but taking care is paramount."
He said he was not sure if all those on board will be identified, but added: "As long as there is material and there is hope for more identifications, we will continue our work".
Seventy-three of the 173 victims positively identified have been returned to the next of kin, officials say.
But police said many families are waiting for more complete sets of remains, or until families and friends who were travelling together have all been identified, before collecting their loved ones.
The Malaysia Airlines Boeing 777 was flying from Amsterdam to Kuala Lumpur when it crashed between Krasni Luch in Luhansk region and Shakhtarsk in the region of Donetsk.
Ukraine's government and several Western leaders say there is strong evidence that pro-Russian separatists shot down the plane with an anti-aircraft system known as Buk.
Russia has consistently denied allegations that it had supplied such missiles or "any other weapons" to the rebels.
The Netherlands has opened an investigation into the disaster, which killed 193 Dutch nationals.
Dutch prosecutors say the charges could include murder, war crimes and intentionally downing an airliner.
The violence in eastern Ukraine erupted in April when separatists declared independence from Kiev following Russia's annexation of Crimea.
More than 2,000 people have died in the fighting and some 330,000 people have been displaced.