Ukraine insists it has proof that pro-Russia rebels fired the missile that downed the Malaysia Airlines passenger plane.
Within hours of the tragedy, the Ukrainian security service posted a recording of what it says was an intercepted phone conversation between a rebel leader and a Russian military officer.
"We have just shot down a plane. That was Miner's group. It fell down outside Enakievo."
"Pilots? Where are the pilots?"
"Set off to search for the shot down plane and take pictures of it. A plume of smoke is visible..."
"How many minutes ago?"
"About 30 minutes ago."
A separate recording captured an alleged conversation between two rebels identified as "Major" and "Greek."
It appears the rebels did not know they had shot down a commercial passenger plane.
Analysts said it's possible that the passenger jet was mistaken for a Ukrainian military aircraft.
Ukraine security service intercept calls:
"The plane broke into pieces in the air, close to Petropavlovskaya mine. There is the first two-hundredth (dead), we have found the first two-hundredth. It's a civilian."
"Well, we are 100% percent sure that it was a civilian plane."
"Are there any weapons?"
"Nothing at all. Civilian belongings, medical scraps, towels, toilet paper."
A third recording, supposedly of a conversation between a fighter and a Cossack commander, said MH17 should not have been flying in the area, with a war going on.
For Ukraine's prime minister, what happened was a terrorist plot.
He said the rebels could not have carried it out without backing from Russia.
"A war against Ukraine, a war against Europe and after these terrorists shot down a Malaysian aircraft, this is the war against the world. Everyone is to be accountable and responsible. I mean everyone who supports these terrorists including Russian Federation and Russian regime," said Prime Minister Arseniy Yatseniuk.
"This is the crime against humanity, all red lines have been already crossed," he added.
Australia's prime minister echoes that sentiment.
"When you have a situation where Russian-backed rebels appeared to have killed Australians using what may well have been Russian-supplied heavy weaponry, Australia takes a very dim view indeed and we want the fullest possible investigation," Prime Minister Tony Abbott said.
World leaders are also calling for a ceasefire between the pro-Russia separatists and Ukrainian forces to ensure safe access to the crash site. - with ANC