..."There's no doubt that there's Iranian intelligence activity throughout Iraq," Army Gen. John P. Abizaid said. "There's no doubt that there's Iranian intelligence activity in Afghanistan."

Abizaid said Iranian activity in Iraq and Afghanistan is particularly troubling because Iranian President Mahmud Ahmadi-Nejad "is very ideological (and) has made an awful lot of threats" against the United States, Israel, and Europe.

The general said improvised explosive device components manufactured in Iran have made their way into Iraq, but there's no provable connection that the Iranian government is directly providing bomb components to terrorists in Iraq.

"I can't tell you whether or not that happened with the orders of the Iranian government," Abizaid said in response to a senator's question. "But I can tell you that terrorists in northeastern Iraq used the Iranian northwestern border to move back and forth across the border."

Regarding possible Iranian government meddling in Iraq, Abizaid said: "We need to look very, very, clearly and effectively with our own intelligence networks to determine how this flow (of IEDs into Iraq) is moving and who has authorized it, if anybody."

An Iran-IED connection, if true, would constitute "a very serious concern," Abizaid said.