WASHINGTON (AP) — Russia’s ambassador to the U.N. has questioned why Ukrainian aviation authorities allowed a passenger flight through an area of armed clashes where anti-aircraft systems were working.

Ambassador Vitaly Churkin was speaking at an emergency meeting of the U.N. Security Council on Friday on the downing of a Malaysian airlines jet, killing 298 people on board.

He said there should be an impartial and open investigation into what happened, and the outcome should not be prejudged.

Churkin said ensuring the security of civilian aviation in a state’s airspace is the responsibility of that state.

Earlier, U.S. Ambassador Samantha Power said the U.S. believes the plane was likely downed by an SA-11 missile fired from an area in eastern Ukraine controlled by pro-Russian separatists.

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