U.S. officials say they have foiled what could have been a major terrorist attack on Washington, D.C. directed by elements within the Iranian government. The capital’s Israeli and Saudi embassies were allegedly the target of two Iranian men, Gholam Shakuri and Manssor Arbabsiar, who is a naturalized U.S. citizen. The men reportedly planned to assassinate Saudi Arabia’s ambassador (picture at left) with bombs. FBI Director Robert Mueller said many lives could have been lost and Attorney General Eric Holder vowed to hold Iran accountable. According to the criminal complaint filed Tuesday, Arbabsiar sought to meet with a representative of a Mexican drug cartel.(Luckily, the "representative" turned out to be a Drug Enforcement Administration confidential source.) Arbabsiar is in custody and Shakuri remains at large. Iran has rejected the accusations, calling them "America's new propaganda scenario." Secretary of State Hillary Clinton said Iran's plot "crosses a line."