MH17 jet 'downed by missile shrapnel,' says Ukraine
Security officials in Ukraine say the downed Malaysia Airlines jet in eastern Ukraine suffered an explosive loss of pressure after it was punctured by shrapnel from a missile.
They say the information came from the plane's flight data recorders, which are being analysed by British experts.
However, it remains unclear who fired a missile, with pro-Russia rebels and Ukraine blaming each other.
Many of the 298 people killed on board flight MH17 were from the Netherlands.
Dutch investigators leading the inquiry into the crash have refused to comment on the Ukrainian claims.
Heavy fighting has prevented an international police force composed of Dutch and Australian officers from reaching the crash site for a second consecutive day.
Ukraine's army said on Monday it had managed to capture two towns near the wreckage in its bid to win back territory from the hands of the rebels.
'Sick and tired'
The international delegation was stopped in Shakhtarsk, a town some 20 miles (30km) away from the area where flight MH17 was brought down.
The town was reportedly struck by shelling, causing residents to flee in cars.
"We are sick and tired of being interrupted by gunfights, despite the fact that we have agreed that there should be a ceasefire," said Alexander Hug, the deputy head of the Organization for Security and Cooperation in Europe (OSCE) team in Ukraine.
They had hoped to secure the site so that the wreckage and human remains can be examined by international crash experts. Most of the bodies have been removed, many of them repatriated to the Netherlands.
Ukrainian security spokesman Andrei Lysenko told reporters on Monday that the plane suffered "massive explosive decompression" after it was hit by fragments he said came from a missile.
Analysis by Richard Westcott, Transport Correspondent
The Dutch team leading the investigation into flight MH17 won't be happy that a Ukrainian security official has apparently jumped the gun on the black box data results. I'm told there were Ukrainian investigators in the room at the UK's Air Accidents Investigation Branch in Farnborough last week when they checked that data, so it seems reasonable to assume this official knows something.
But still, the Dutch are hoping to publish their own more detailed and more rounded report later this week, pooling together everything they've learned so far.
Several former accident investigators have said to me that the black boxes will only tell us so much. To state the obvious, they are designed to highlight mechanical problems, not identify missile attacks. The flight data recorder could pick up evidence of an aircraft decompression, but it won't necessarily tell us why. The cockpit voice recorder may also pick up the sound of an external explosion.
In the end, experts will need more than the black boxes to work out what happened. They'll need to see the wreckage, the bodies and the American satellite data which the US says shows a missile was fired from rebel territory.
It's also worth remembering, even if all the black box data appears to tally with a missile strike, it won't tell us who fired it. Both sides in this conflict possess the same weapon.
Earlier, UN human rights chief Navi Pillay said the downing of the Malaysia Airines jet could constitute a "war crime".
She demanded a "thorough, effective, independent and impartial investigation" into the "shooting down" of the jet.
Ms Pillay spoke as the latest UN report on Ukraine suggested at least 1,129 people have been killed and 3,442 wounded in the Ukraine conflict since mid-April.
The conflict has displaced more than 200,000 people, many of whom have fled east to neighbouring Russia.
In other developments:
- Russian Foreign Minister Sergei Lavrov says he hopes OSCE monitors would be deployed on the Ukraine-Russia border in the next few days
- The army is trying to take control of two main roads and vital supply lines from Russia to rebels in their stronghold of Donetsk
- Reports of several civilian causalities from shelling in the cities of Horlivka, Donetsk and Luhansk
- Human Rights Watch urges both sides against using unguided Grad rockets on civilian areas