Feinstein Questions Whether Iran Backing More Plots in Wake of Alleged Assassination Scheme

Sen. Dianne Feinstein thumbs through documents as she speaks on Capitol Hill in Washington Oct. 4. (AP)

A top senator warned that the United States should be on "alert" about other Iran-driven terror plots in the wake of the alleged scheme to assassinate the Saudi ambassador to Washington.

Sen. Dianne Feinstein, D-Calif., chairwoman of the Senate Intelligence Committee, said she's been aware of the investigation for about a month and that "intelligence indicates" there could be "problems" elsewhere.

Feinstein declined to get into detail and stressed that she wasn't saying other diplomats are necessarily in danger. But she raised the question of whether an Israeli ambassador or American ambassador could also be targeted, if Iran's special operations Quds Force was involved in this plot as alleged.

"It's hard for me to believe that there is just one plot involving the U.S. ... I think we need to explore whether there are other plots going on in other countries," she said Wednesday. "I'm not saying there's a broader plot. I'm just saying that we need to look at that."

Other senators will be briefed on the assassination plot Thursday.

The State Department acknowledged that the plotters were looking at other targets but assured that the administration believes the entire operation was short-circuited after the Justice Department went public with the investigation.

"I would simply say that we do believe that there were other targets, and there were follow-on notions by these plotters. But we do believe that the entire plot now has been disrupted," State Department spokeswoman Victoria Nuland said.

Aside from aiming to assassinate the Saudi ambassador to the United States, the plotters apparently were looking at possible attacks on the Saudi and Israeli embassies.

According to the Justice Department, the lone suspect in custody initially inquired about the possibility of attacks on a Saudi Arabian embassy. A separate alert obtained by Fox News outlined a possible plot regarding attacks on the Saudi embassies in Washington, D.C., and in Buenos Aires, Argentina.

Nuland, without getting into detail, acknowledged that a top State official had called Argentina's government in the wake of the investigation.

Meanwhile, U.S. lawmakers continue to speculate over whether the top echelons of the Iranian government knew of the plot.

Feinstein said she doesn't know whether, for example, Iranian President Mahmoud Ahmadinejad was aware. But she said the Quds Force would probably not have proceeded without high-level approval from the Islamic Revolutionary Guard Corps and other elements.