In a statement on Friday, the military said the American aircraft, including P-8 Poseidon and MQ-9 and RQ-4 drones, were intercepted by a domestically-manufactured Karrar turbojet-powered drone.
On the second day of the exercises, dubbed Zolfaqar-99, the three aircraft entered the ADIZ while they had already been monitored by the Iranian integrated air defense network from kilometers away, the statement said.
It noted that the intruding aircraft were intercepted after they ignored warnings to stay away from the drills area, Press TV reported.
The Iranian military said the aircraft veered away and left the drills area after the Karrar drone was launched.
Forces from the Army Ground Force, Navy, Air Force, and Air Defense have taken part in the war game that covers an area of 2 million square kilometers in eastern parts of the Strait of Hormuz, Makran Coast, Sea of Oman, and northern parts of the Indian Ocean, down to the 10-degrees latitude.