WASHINGTON — An Iranian jet fighter pursued an American surveillance drone over the Persian Gulf this week.
The long-distance chase ended, however, following a warning radio transmission from an American escort plane, Pentagon officials said Thursday.
The chase, which occurred Tuesday, followed a more serious encounter in November, when Iranian warplanes fired on, but missed, a Predator drone carrying out a similar classified surveillance mission.
Pentagon officials said that in both instances the drones were in international airspace.
Even so, the episodes illustrate the chance of unintended hostilities arising from encounters between remotely piloted surveillance craft and Iranian warplanes in the heavily militarized Persian Gulf.
The Pentagon press secretary, George Little, said that in the episode on Tuesday, an Iranian F-4 jet fighter approached within 16 miles of the Predator, which was being escorted by a pair of American military aircraft. U.S. officials did not say what type of American planes were involved.
“The Iranian aircraft departed after a verbal warning,” Little said. An initial Pentagon statement said one of the American escort planes had fired a flare to warn the Iranian jet away but later retracted that report.
Little said that after the encounter in November, the United States sent a message to Iran that the American military would “continue to conduct surveillance flights over international waters consistent with longstanding practice and our commitment to the security of the region.”
“We also communicated that we reserve the right to protect our military assets as well as our forces and will continue to do so going forward,” Little said.
Iran deployed two Russian-made Su-25 jets known as Frogfoots in the November episode, which was the first known instance of Iranian warplanes firing on an American surveillance drone.
The Predator model involved in both encounters resembles an upside-down flying spoon and is not easily confused with a piloted jet fighter.
In 2011, an RQ-170 surveillance drone operated by the CIA rather than the military crashed in Iran during a mission that was believed to have been intended to map suspected nuclear sites.
That episode came to light only after Iran announced that it had electronically attacked the drone and guided it to a landing.
U.S. officials said the drone had crashed after a technical malfunction.