The search for victims of the Malaysia Airlines crash in Ukraine must go on as only about 200 bodies appear to have been found so far, Dutch officials say.
Forensics expert Jan Tuinder said his team had begun counting the bodies that earlier arrived in the town of Kharkiv.
The first bodies, which were moved out of territory held by pro-Russian rebels, are due to be flown to the Netherlands on Wednesday.
The plane crashed in a rebel-held area on 17 July, killing all 298 on board.
American intelligence officials on Tuesday said evidence suggested the rebels may have shot down the jet “by mistake”, and that no direct link to Russia had been found.
However, Russia “created the conditions” for downing flight MH17 by arming the rebels, the officials were quoted as saying by the Associated Press.
Russia has repeatedly said Ukrainian government forces are to blame for the attack, but the US officials said that Russian claims were “not plausible”.
Speaking at a news conference in the town of Kharkiv, Mr Tuinder said they would have to go back to the crash site to carry out another search.
“We will not leave until [all] remains have left this country so we will have to go on and bargain again with the people over there,” he said.
It was widely reported that more than 280 bodies had been on the train, which brought the remains to Kharkiv.
However, Mr Tuinder later clarified that a reliable source who was there during the loading of the bodies on to the train had given a figure of 200.
He said this number could increase as the forensics teams go through the refrigerated wagons.
Meanwhile, in a statement, Interpol said international experts in Kharkiv would carry out preliminary examinations on the bodies before their transport to the Netherlands.
Most of those who died when the Boeing 777 crashed were Dutch, and the first remains are due to be flown from Kharkiv to the Dutch city of Eindhoven on Wednesday.
From there, they will go to a facility in the city of Hilversum for identification – a process which Dutch officials say could take months.
The Dutch government has declared Wednesday a national day of mourning.
Interpol said the remains of victims recovered so far from the crash site had been “labelled and numbered before being transported in refrigerated freight wagons from Donetsk to Kharkiv”.
Monitors from the Organization for Security and Co-operation in Europe examining the wreckage found that major pieces of the plane had been cut into and that large parts now looked different.
Countries directly affected by the disaster, such as the Netherlands, Australia, and the UK, have been concerned that the crash site was not properly sealed off, with the risk that valuable evidence could be put at risk.
The plane’s “black box” flight recorders, which were handed over by rebels to Malaysian officials, will be flown to a laboratory in the UK for analysis.
Why are the black boxes being examined in the UK? The British Air Accidents Investigation Branch (AIIB) tell me they are one of only two so-called “replay units” in Europe with the necessary equipment to listen to what has been recorded on the cockpit voice recorder. The other is in France.
They have the kit to analyse in minute detail what can be heard in the last few minutes of flight MH17. The information is incredibly sensitive so investigators gather in a sealed room so that only those that should be listening can listen.
There are four speakers on the walls creating a surround sound – anything to help the investigators hear exactly what went on. They may even hear any explosion.
The AIIB won’t tell me when they expect to get their hands on the black boxes. But investigators are confident that, depending on the extent of the damage, they can retrieve information from the boxes within 24 hours.
New Russia sanctions
European Union foreign ministers have announced they will impose more sanctions against Russia over its alleged backing for the rebels – something Moscow denies.
They said the list of individuals and groups covered by EU sanctions would be broadened and a new list drawn up by EU ambassadors by Thursday at the latest.
“The word is ‘cronies’: the cronies of [Vladimir] Putin and his clique in the Kremlin are the people who have to bear the pressure,” British Foreign Secretary Philip Hammond said after the meeting in Brussels.
Ministers will also ask the European Commission to look at an embargo on new arms sales to Russia and to increase punitive measures against Russia in the financial and energy sectors.
Both the EU and the US imposed sanctions on Russia following its annexation of Crimea in March and the outbreak of hostilities in eastern Ukraine.
Meanwhile, the conflict between Ukrainian government forces and rebels has continued, with reports of fighting round Donetsk and Luhansk.
Ukrainian Interior Minister Arsen Avakov said the army had captured the strategically important town of Severodonetsk, located some 140km (87 miles) from the key rebel stronghold of Donetsk.
Parliament has also approved the call-up of more military reserves and men under 50.
Thirteen Ukrainian soldiers were killed over the past 24 hours, a Ukrainian security official said. Three of them died as a bus packed with explosives blew up at a roadblock.
The fighting in eastern Ukraine erupted in April and is believed to have claimed more than 1,000 lives.