* Australian PM Abbott expresses revulsion, says Russian-backed rebels behind crash
* Russian ambassador called in, questions raised over Putin's G20 visit
* "Russian-supplied equipment" used to down plane
* 28 Australians dead in Malaysia Airlines downing (Adds comment from Abbott news conference, Hockey comment, updates Australian death toll)
By Matt Siegel
SYDNEY, July 18 Australian Prime Minister Tony Abbott blamed Russia on Friday for the shooting down of a Malaysia Airlines passenger jetliner over eastern Ukraine that killed all 298 people on board.
Abbott appeared to go further than other Western leaders in apportioning blame over the crash, demanding that Moscow answer questions about the "Russian-backed rebels" that he said were behind the disaster, which claimed 28 Australian lives.
The Russian ambassador to Australia was called in to discuss the matter, and Abbott said he was unhappy with the response.
"I have to tell you that the initial response of the Russian ambassador was to blame Ukraine for this and I have to say that is deeply, deeply unsatisfactory," Abbott told reporters.
"We all know that there are problems in Ukraine. We also know who is very substantially to blame for those problems and the idea that Russia can somehow say that none of this has anything to do with them because it happened in Ukrainian air space frankly does not stand up to any serious scrutiny."
Australia is due to host Russian President Vladimir Putin and other world leaders at a G20 Leaders Summit in November. Asked if he would still welcome Putin if Russia was proved to be behind the accident, Abbott hinted there may be repercussions.
"That's a fair question, let's just wait and see exactly what turns out to have happened here," Abbott said in an earlier interview with Melbourne-based 3AW Radio.
Treasurer Joe Hockey indicated Putin was still expected at the summit.
"It is an economic summit," Hockey told the Bloomberg news agency in an interview when asked whether Putin was likely to attend. "In an unrelated way, we can't allow individual events to prevent people from meeting together to resolve differences."
In a sombre speech before parliament, Abbott earlier said he was "filled with revulsion" and blamed anti-Kiev separatists for shooting down the plane.
"This is a grim day for our country and it's a grim day for our world. Malaysian airlines MH17 has been shot down over the eastern Ukraine, it seems by Russian-backed rebels," he said.
Ukrainian authorities have accused "terrorists" - militants fighting to unite eastern Ukraine with Russia - of shooting down the Boeing 777-200. The rebels denied responsibility.
Putin blamed Kiev for renewing its offensive against rebels two weeks ago after a ceasefire failed to hold. The Kremlin leader called the crash a "tragedy" but did not say who brought the Malaysian plane down.
U.S. Vice President Joe Biden said the downing of the airliner apparently was "not an accident" and that it was "blown out of the sky".
Abbott and his government lashed out at Russia directly, however, saying it was no accident that rebels armed with Russian-made military hardware capable of shooting down passenger jets would use them for that purpose.
"This is no light thing; this is not something that can just be dismissed as a tragic accident when you have Russian proxies using Russian-supplied equipment to do terrible things," Abbott said. (Additional reporting by Jane Wardell and Lincoln Feast in SYDNEY; Editing by Paul Tait and Robert Birsel)