Kharkiv, Ukraine (BBN)-The first bodies recovered from the Malaysia Airlines plane which crashed in Ukraine last week are to be flown to the Netherlands for identification.

A day of mourning is being held to mark the occasion, more than five days after the aircraft was downed in a rebel-held area in eastern Ukraine, reports BBC.

Meanwhile US intelligence officials said they believed pro-Russian rebels had shot down the jet by mistake.

But no direct link to Russia itself had been found, they added.

The plane crashed in a rebel-held area after apparently being hit by a missile on 17 July killing all 298 people on board, most of whom were Dutch.

A refrigerated train carriage carrying around 200 bodies from the crash site arrived in the government-held city of Kharkiv on Tuesday.

The operation to find the remaining bodies and secure crucial evidence continues.

Russia has repeatedly said Ukrainian government forces are to blame for the attack, but the US officials said that Russian claims were “not plausible”.

NATIONAL MOURNING

The first bodies from flight MH17 are due to arrive in Eindhoven at 16:00 local time (14:00 GMT) after a farewell ceremony attended by Ukrainian officials in Kharkiv.

The Dutch royal family and the prime minister Mark Rutte will meet the plane.

The bodies are then due to be taken to the Korporaal van Oudheusden barracks for identification.

Rutte said that process could “take weeks or even months”.

The Dutch government has declared Wednesday a day of national mourning.

In a separate process, the aircrafts flight data recorders have been handed over to Dutch authorities by Malaysian officials.

The devices, also known as ‘black boxes’, will be sent to Farnborough in the UK for analysis.

It’s a briefing by US intelligence officials that’s left many scratching their heads.

Since the crash, officials in Washington have been playing up Russian’s involvement in attacking the plane.

Secretary of State John Kerry in particular pointed the finger of blame firmly at Moscow and said evidence would be produced very soon. That’s what was expected.

But while senior intelligence officials said Russia had “created the conditions” for the plane’s shooting down, there was, as yet, NO evidence of the direct involvement of the Russian government.

They said that while it’s likely separatists brought down the Malaysian Airlines plane… it was by mistake.

So why would the White House want to wind down rhetoric, in the way it appears to many it has?

It could be around the difficult question about what to do with Russia if there IS evidence it was directly involved. It is, after all, a country heavily involved in international diplomatic efforts regarding Iran, Syria, and North Korea, and a country a lot of Europe relies on for its gas.

For the White House, the question of how to put enough pressure on President Putin to stop his country backing rebels and undermining Ukraine’s sovereignty, is still, very clearly, a troubling one.

US intelligence officials, speaking anonymously at a press briefing on Tuesday, said the “most plausible explanation” for the shooting down of the plane was that rebels mistook it for another aircraft.

“Five days into it, it does appear to be a mistake,” one of the officials said.

They went on to say that Russia was responsible for creating the conditions that led to the crash.

“It’s a solid case that it’s a SA-11 that was fired from eastern Ukraine under conditions the Russians helped create,” one official said.

However, there was no direct evidence of direct Russian involvement in the firing of the SA-11 surface-to-air missile believed to have caused the crash, the officials said.

Nor did the US know that the Ukrainian rebels possessed SA-11 missiles until after the plane was shot down, the officials added.

The officials said that their findings were based in part on social media postings and video released in recent days.

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.

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 on Tuesday the army had captured the strategically important town of Severodonetsk, located some 140km (87 miles) from the key rebel stronghold of Donetsk.

The fighting in eastern Ukraine erupted in April and is believed to have claimed more than 1,000 lives.

BBN/SS-23July14-11:00am (BST)