The charge made by military spokesman U.S. Army Brig. Gen. Kevin J. Bergner at a news conference was the first time U.S. officials have accused Iranian officials of helping to plan an attack on U.S. troops, The New York Times reported.

U.S. officials have previously charged that the Iran Revolutionary Guard is supplying Iraqi insurgents with weapons and training.

In the Jan. 20 Karbala attack, the attackers wearing uniforms that appeared American killed one soldier in a raid and kidnapped four others whose bodies were found later.

Bergner also said Monday that the Iranian Revolutionary Guard Corps used Hezbollah members to train and arm Shiite Iraqi insurgents, the Times reported.

Bergner said the Karbala accusation was supported by interrogations of captured high-level Iraqi insurgents and a senior Hezbollah operative, the Times reported.