BAGHDAD, July 23 (UPI) -- The U.S. military should prepare for attacks by "advanced weapons" in Iraq, a spokesman for the Islamic Army in Iraq said.

Ali a-Na'imi, a spokesman for the Sunni IAI insurgency, said in an interview with the independent, non-profit media outlet The Media Line that the insurgency was in a constant quest for new methods of attack.

The group claims on its Web site its operations in Iraq have killed at least 28 U.S. soldiers recently, and Na'imi warned of further attacks using "advanced weapons."

"God willing, soon you will hear news about advanced weapons, which will stun the occupation army and will gain a victory for Allah's sake," he said.

The IAI formed in the wake of the U.S.-led invasion in 2003. Its leadership allegedly comprises former Iraqi military officers.