BAGHDAD - Iran is using the Lebanese Shiite militia Hezbollah as a "proxy" to arm Shiite militants in Iraq and Tehran's Quds force had prior knowledge of a January attack in Karbala in which five Americans died, a US general said Monday.

An Iraqi woman is photographed by US soldiers from Charlie Company, 2nd Battalion, 3rd Infantry Regiment, 3rd Stryker Brigade Combat Team, Second Infantry Division as they conduct a search of the Dora neighborhood of Baghdad, Iraq Sunday, July 1, 2007. [AP]

US military spokesman Brig. Gen. Kevin J. Bergner said a senior Lebanese Hezbollah operative, Ali Mussa Dakdouk, was captured March 20 in southern Iraq. Bergner said Dakdouk served for 24 years in Hezbollah and was "working in Iraq as a surrogate for the Iranian Quds force."

The general also said that Dakdouk was a liaison between the Iranians and a breakaway Shiite group led by Qais al-Kazaali, a former spokesman for cleric Muqtada al-Sadr. Bergner said al-Kazaali's group carried out the January attack against a provincial government building in Karbala and that the Iranians assisted in preparations.

Al-Khazaali and his brother Ali al-Khazaali, both captured in March, have told US interrogators that they "could not have conducted it (the Karbala attack) without support from the Quds force," Bergner said.

Documents captured with al-Khazaali showed that the Quds Force had developed detailed information on the US position at the government building, including "shift changes and defense" and shared this information with the attackers, the general said.

US officials at the time of the Karbala attack said it was unusually sophisticated, with the attackers dressed in US uniforms to get close to the building, and suggested Iran may have had a role in it.

The US military in the past has accused the Quds Force - the external arm of Iran's elite Revolutionary Guards - of arming and financing Iraqi extremists to carry out attacks on US and Iraqi forces. Tehran has denied the US accusations.

Bergner said Iraqi extremists were taken to Iran in groups of 20 to 60 for training in three camps "not too far from Tehran." When they returned to Iraq, they formed units called "special groups" to carry out attacks, bombings and kidnappings, he said.

Dakdouk helped train and organize the groups, making four visits to Iraq in the past year after a May 2006 trip to Iran, the general said. Hezbollah, he said, helps the Iranians as a "proxy ... to do things they didn't want to have to do themselves in terms of interacting with special groups."

"Our intelligence reveals that the senior leadership in Iran is aware of this activity," he said. Asked if Iran's supreme leader Ayatollah Ali Khamenei could be unaware of the activity, Bergner said "that would be hard to imagine."