In some of its most direct accusations against Iran yet, the US military said yesterday senior leaders in Tehran know about operations in which Iran's Qods Force foments violence in Iraq.
Military spokesman Brigadier-General Kevin Bergner said the Qods Force was also using the Iranian-backed Lebanese Shi'ite militia group Hizbollah to sponsor militant activity in Iraq.
Iran does not officially acknowledge the Qods Force. Military experts and some exiled Iranians say it is a wing of Iran's Revolutionary Guards that operates abroad and reports directly to Iran's Supreme Leader Ayatollah Ali Khamenei.
Brigadier-General Bergner said the Qods Force was involved in a brazen attack in the city of Kerbala in January when gunmen disguised as Americans made their way into a government compound and killed one US soldier and seized four others whom they later killed.
Washington has long accused the Qods Force of arming and training Shi'ite militants who attack US and Iraqi soldiers but previously it said it was not clear whether these actions were carried out with the full knowledge of Iran's leadership.
Shi'ite Iran denies involvement in violence in Iraq and blames the US-led invasion in 2003 for the bloodshed.
"Our intelligence reveals that senior leadership in Iran is aware of this activity," Brigadier-General Bergner told a news conference. "We also understand that senior Iraqi leaders have expressed their concerns to the Iranian government about the activities."
Asked if it was possible that Qods Force support was being provided without the knowledge of Mr Khamenei, he said: "That would be hard to imagine".
Brigadier-General Bergner said the US had discovered the existence of three small camps near Tehran where Iraqi Shi'ite militants were trained by Qods Force and Hizbollah operatives. Between 20-60 militants were trained at any given time, he said.
The Kerbala attack was one of the boldest against US troops. The attackers spoke English, wore American-looking uniforms and carried US-type weapons, which got them through Iraqi checkpoints to reach the compound.
"The Qods Force had developed detailed information regarding our soldiers' activities, shift changes and defences, and this information was shared with the attackers," Brigadier-General Bergner said.
He also said a Hizbollah veteran, Ali Mussa Daqduq, was detained in southern Iraq in March. Mr Daqduq was there to organise secret cells to mirror Hizbollah's structure in Lebanon, he said.
A Hizbollah spokesman in Beirut said he was aware of the US accusations, but had no immediate comment.
Iran's Defence Minister Mostafa Mohammad Najjar dismissed on Sunday as a "sheer lie" US accusations that Iran was militarily intervening in Iraq and supported Iraqi militants, the official Irna news agency reported.
The fresh charges against Iran come at a sensitive time. On Sunday, Iraqi Foreign Minister Hoshiyar Zebari said he was pressing the US and Iran to hold a second round of talks in Baghdad to follow up a landmark meeting on May 28, but that no date has been set.
The May meeting between US Ambassador to Iraq Ryan Crocker and his Iranian counterpart, Hassan Kazemi-Qomi, was the most high-profile meeting of the two foes in almost three decades.