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By Matt Siegel
SYDNEY, July 18 (Reuters) - Australian Prime Minister Tony Abbott said on Friday it appeared that "Russian-backed rebels" were behind the shooting down of a Malaysia Airlines passenger jetliner over eastern Ukraine that killed all 298 people on board.
Ukraine's state security chief has accused Russian military intelligence officers of involvement with pro-Russian rebels in the downing of the airliner on Thursday, but Western leaders have until now been less quick to assign blame.
Abbott blamed anti-Kiev separatists for shooting down the plane during a sombre speech before parliament in which he confirmed that 27 Australian citizens had died in the crash.
"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. (Reporting by Matt Siegel; Editing by Paul Tait)