FILE PHOTO: A plane flies towards the rising sun behind power lines in Los Angeles, California, United States, October 1, 2015. REUTERS/Lucy Nicholson

WASHINGTON (Reuters) - The U.S. Federal Aviation Administration on Thursday issued an emergency order prohibiting U.S. operators from flying in an overwater area of Tehran-controlled airspace over the Strait of Hormuz and Gulf of Oman due to heightened tensions.

In a separate advisory to operators, FAA said according to flight tracking applications, the nearest civil aircraft was operating within around 45 nautical miles of a U.S. Global Hawk drone when it was shot down by an Iranian surface-to-air missile this week.

“There were numerous civil aviation aircraft operating in the area at the time of the intercept,” FAA said.

The agency said it remained concerned about the escalation of tension and military activity within close proximity to high volume civil aircraft routes as well as Iran’s willingness to use long-range missiles in international airspace with little or no warning.