Prime Minister Tony Abbott has again called for a transparent, international investigation into the attack on Malaysian Airlines flight MH17 in which 28 Australians were among 298 passengers and crew killed.

Mr Abbott says Foreign Minister Julie Bishop will fly to the United States this evening to campaign for an international investigation into what took place.

• Thieves targeted crash victims
• Should MH17 have been flying through a war zone?
• Bishop: Russia’s refusal to hold talks ‘extraordinary’
• GALLERY MH17: The world mourns
• VIDEO Witnesses capture vision of plane crashing, Abbott speaks 

Flight MH17 was shot down by a surface-to-air missile which left bodies and smouldering debris scattered across fields in eastern Ukraine – pro-Russian separatists are being blamed for the attack.

Mr Abbott says the priority is gaining access to the site where the plane came down, but gunman have prevented international investigators from securing an access corridor to the wreckage.

A team of 17 investigators from the Organisation for Security and Cooperation in Europe were allowed to examine the wreckage for nearly 75 minutes, before being forced out by gunmen.

Six officers from the Department of Foreign Affairs and Trade have been deployed to Kiev, and more are on their way, including a five-member emergency response team as well as a team of AFP investigators.

Mr Abbott says the Australian Government will do whatever is humanly possible to ensure the “matter is absolutely thoroughly investigated” and to “bring the perpetrators to justice”.

“Right now, for all we know – because this site is controlled by Russian-backed rebels – bodies remain strewn over the fields of the eastern Ukraine and armed rebels are trampling the site,” the Prime Minister said.

“So it is absolutely vital that an independent, international investigation begin as soon as possible so that we can identify and recover the remains of all the Australians onboard.

“And we are working urgently with our international partners to that end.”

More to come.