Here is an excerpt from J. David Goodman's article in The New York Times:

"Federal authorities foiled a plot by men linked to the Iranian government to kill the Saudi ambassador to the United States and to bomb the embassy of Saudi Arabia in Washington, Attorney General Eric H. Holder Jr. said in a news conference on Tuesday. Mr. Holder said the plot began with a meeting in Mexico in May, “the first of a series that would result in an international conspiracy by elements of the Iranian governmentâ€