The suspects and a number of weapons were seized during a raid on a rural farm compound in eastern Iraq, near the Iranian border, according to a military statement.
"The suspects may be associated with a network of terrorists that have been smuggling explosively formed projectiles (EFPs), other weapons, personnel and money from Iran into Iraq," the military said, referring to powerful, armor-piercing roadside bombs that have killed hundreds of U.S. soldiers in recent months.
The announcement came just days after Washington said it was ready to hold new direct talks with Iran on the deteriorating security situation in Iraq amid U.S. allegations that Tehran is supporting violent Shiite militias in the country.