American-registered commercial aircraft were barred from entering Iranian-administered airspace in the Strait of Hormuz and Gulf of Oman on Friday, just 24-hours after the Iran Revolutionary Guard Corps (IRGC) downed a U.S. military surveillance drone.

Dutch KLM and Australian carrier QANTAS have also voluntarily agreed not to overfly the area.

The Federal Aviation Administration (FAA) made the call in an emergency warning that pointed to a “potential for miscalculation or misidentification” in the region after an Iranian surface-to-air missile brought down a U.S. Navy RQ-4A Global Hawk, an unmanned aircraft with a wingspan larger than a Boeing 737 jetliner and costing over $100 million.

“All flight operations in the overwater area of the Tehran Flight Information Region (FIR) (OIIX) above the Persian Gulf and Gulf of Oman only are prohibited until further notice due to heightened military activities and increased political tensions in the region, which present an inadvertent risk to U.S. civil aviation operations and potential for miscalculation or mis-identification,” the FAA said in a press advisory.

#FAA issued #NOTAM warning pilots that flights are not permitted in the overwater area of the Tehran Flight Information Region until further notice, due to heightened military activities and increased political tensions. https://t.co/BQ2GOeFSEn pic.twitter.com/4t1OWEzkYZ — The FAA (@FAANews) June 21, 2019

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 the U.S. drone when it was taken down.

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

Earlier Thursday, United Airlines said it had suspended flights from New Jersey’s Newark airport to the Indian financial capital of Mumbai following a safety review.

“Given current events in Iran, we have conducted a thorough safety and security review of our India service through Iranian airspace and decided to suspend our service,” United said on its website, but did not say how long the suspension would last.

Australian airline QANTAS also announced it will reroute flights away from the Strait of Hormuz and Gulf of Oman. The carrier said it would affect its flights between Australia and London and stressed its flights pass over the region at 40,000 feet.

Dutch airline KLM has also followed suit.

The upheaval in Mideast air travel comes just three-days after the Pentagon released new images which officials said offered more evidence operatives from the IRGC were responsible for last week’s attacks on oil tankers in the Gulf of Oman.

The U.S. military said the photos, taken from a Navy helicopter, showed Iranian forces removing an unexploded mine from the hull of the Japanese-owned Kokuka Courageous oil tanker.