Sources confirmed to ABC News that post-arrest interrogations had led to the new allegations, and also claimed that the men had spent time in a military training camp on the Lebanese-Syrian border, where they were reportedly taught how to blow up buildings and carry out assassinations. Experts believe the Iranian Revolutionary Guard, which is closely linked to the country's ruling clerics, established the camp in 1983 to train members of the then-nascent Lebanese paramilitary group Hezbollah. Both the Revolutionary Guard and Hezbollah are designated as terrorist organizations by the U.S. government.
In November, Attorney General Eric Holder said that the U.S. had disrupted a plot to kill the Saudi ambassador to the U.S., and alleged that the plan was "conceived, sponsored [and] directed from Iran" by a faction of the government. A member of the Quds force of the Revolutionary Guard was charged in the criminal complaint.
The crisis in Syria has been seen as another important battleground between Iran and the Saudis, with Iran reportedly providing much needed financial assistance to the Syrian regime through its other regional ally Iraq, just as Saudi Arabia has led the Arab League's incremental isolation of the Assad regime.
The alleged plotters are set to appear in court in February. Though they acknowledge that they left Bahrain without going through the proper border authorities, the men deny the rest of the accusations.
The year-long unrest in Bahrain has killed at least 50 people. A report published in November by an independent panel of human rights experts appointed by Bahrain's king found that security forces used excessive force and used systematic torture in detention. The commission also found no evidence of a "clear link between the events in Bahrain and Iran."