The Iranian military threatened to shoot down two Navy surveillance aircraft Saturday as they flew over international waters over the Straits of Hormuz, defense officials said.

The aircraft, reportedly a P-8 Poseidon with a crew of nine and an EP-3 Eres with a crew of 24, were flying "routine patrols" when an Iranian air defense station contacted them using ground-to-air radio communications, Navy officials said.

The Iranians told the pilots that they were flying "near Iranian airspace, and if they did not change course immediately 'we will fire Iranian missile,'" according to a statement from U.S. Naval Forces Central Command and the U.S. Fifth Fleet headquarters in Bahrain.
 
The Iranian air defense station made the threats in three separate radio calls.

The two Navy aircraft each told Iranian officials via radio: "This is a coalition aircraft conducting routine operations in international airspace." Both continued their patrols, Navy officials said.

U.S. officials consider the interaction "unprofessional due to the threatening nature of the Iranian warning," Cmdr. William Urban, a Navy spokesman, said in a statement released Tuesday. "This interaction was not assessed as unsafe because the aircraft were out of known Iranian surface to air weapons range."

Iran’s territorial waters extend 12 miles into the sea, in accordance with international maritime law.

Navy officials declined to identify the aircraft. The incident was first reported by Fox News, which said one was a P-8 Poseidon and the other a EP-3 Eres.

It's the latest sign of Iranian aggression and provocations with the U.S. Navy.

Last month, four Iranian warships harassed the U.S. Navy destroyer Nitze in the Strait of Hormuz.

Also in August, a U.S. Navy patrol boat fired warning shots at a small Iranian boat that charged head-on at the American vessel.