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U.S. foils attempt to assassinate Saudi ambassador

U.S. officials tell NBC News that two Iranians -- one an Iranian American -- have been indicted on charges that they plotted to kill a Saudi diplomat, Ambassador Adel al Jubeir, the Saudi ambassador to the United States.

The indictment alleges that defendants "would use a weapon of mass destruction" against the ambassador, a senior law enforcement official adds.

The indictment is the result of a sting operation conducted by the FBI and the Drug Enforcement Agency.

The lead suspect, an Iranian-American, approached a DEA informant in May asking for help from the Zetas drug cartel to assassinate the Saudi ambassador, according to senior law enforcement officials. The Iranian-American believed the DEA informant worked for the Zetas drug cartel in Mexico.

The DEA then brought in the FBI, which set up the sting in detail.   

The White House issued this statement: "The president was first briefed on this issue in June and directed his administration to provide all necessary support to this investigation. The disruption of this plot is a significant achievement by our intelligence and law enforcement agencies, and the president is enormously grateful for their exceptional work in this instance and countless others."

*** UPDATE *** And perhaps the most explosive part of this plot -- it's linked to elements inside the Iranian government. As a Justice Department press release says, "Two individuals have been charged in New York for their alleged participation in a plot directed by elements of the Iranian government to murder the Saudi Ambassador to the United States with explosives while the Ambassador was in the United States."