GENEVA (AFP) - The downing of flight MH17 over eastern Ukraine was a "hideous crime" and hurdles to a probe of the tragedy are an "outrage", global airline federation IATA said on Tuesday.
"The passengers and crew aboard the aircraft were the victims of a hideous crime. It was also an attack against the air transport system," said Tony Tyler, head of the International Air Transport Association.
Last Thursday's disaster, which claimed 298 lives on the Malaysian Airlines plane, was allegedly the result of a missile attack by pro-Russian rebels in Ukraine.
The rebels were then accused of blocking access to the crash site and tampering with evidence.
On Tuesday, they handed over the plane's black boxes, and declared a localised truce to allow international experts full access to the fields in east Ukraine where the plane went down.
"The investigation must also start quickly and with total freedom and access. Actions over the weekend which slowed down progress on both of these priorities were an outrage to human decency," Mr Tyler said in a statement.
"For over four days we witnessed appalling sights from the crash scene," he said.
"Governments must set aside their differences and treat the victims and their families with the dignity they deserve - and this includes urgently securing the site," he added.
It was only on Monday that rebel forces allowed forensic experts from The Netherlands - which had 193 citizens on board the flight - to examine bodies which were being kept in refrigerated train cars away from the sweltering summer heat.
A train carrying the remains of 280 victims arrived Tuesday in the city of Kharkiv, which is controlled by the Ukrainian government.
Mr Tyler also called for a review of how air-space safety assessments are conducted.
"Governments and air navigation service providers inform airlines about the routes that they can fly and with what restrictions. Airlines comply with that guidance," he said.
"Malaysia Airlines was a clearly identified commercial jet. And it was shot down - in complete violation of international laws, standards and conventions - while broadcasting its identity and presence on an open and busy air corridor at an altitude that was deemed to be safe," he added.