Nearly 300 people are believed to have been killed when a Malaysia Airlines jet crashed today in eastern Ukraine.  A Ukrainian official says pro-Russian militants shot the plane down.  The official blames "terrorists" who he says used a ground-to-air missile to bring down the Boeing 777 about 25 miles from the Russian border.  U.S. officials are trying to determine whether there were any Americans on board.  A Ukrainian official says the plane that took off from Amsterdam was carrying 23 American citizens.  

President Obama calls the crash a "terrible tragedy" and State Department spokesman Jen Psaki says the U.S. is closely monitoring the situation in Ukraine.  She refused to speculate on the claims the airliner was brought down by a ground-to-air missile.  Dutch Prime Minister Mark Rutte says he is "deeply shocked" and is returning to the Netherlands from a summit in Brussels.  Tour operators in the Netherlands say they had booked dozens of Dutch citizens onto the flight.  Malaysia's prime minister has also expressed his shock at the tragic news. 

Meanwhile, Ukrainian rebels claim to have found the jet's black box.  The report comes from Russia's Interfax news agency.  In light of the crash, major air carriers are avoiding the east Ukraine area.  Lufthansa, Air France and Virgin Atlantic are all avoiding the airspace.  Earlier this year, the U.S. State Department had warned citizens to defer all travel to two eastern regions because armed separatist groups control the areas. 

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