The U.S. military in Iraq says it has arrested a key bombing suspect who was trained by Iranians.

The military says the suspected militant ran a cell of explosive experts in Baghdad and was captured Tuesday without a struggle.

U.S. commanders believe the suspect is affiliated with Hezbollah. This is a Shiite militant group with its power base in Lebanon, but with strong links to Iran.

Iran is accused of aiding and training Shiite militia groups in Iraq. Iran denies the charges.