DUBAI, United Arab Emirates (AP) Major airlines from around the world on Friday began rerouting their flights to avoid areas around the Strait of Hormuz following Irans shooting down of a U.S. military surveillance drone there, as America warned commercial airliners could be mistakenly attacked .

The Federal Aviation Administration warned of a potential for miscalculation or misidentification in the region after an Iranian surface-to-air missile on Thursday 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. The U.S. said it made plans for limited strikes on Iran in response, but then called them off.

Australias Qantas, British Airways, Dutch carrier KLM, Emirates, Germanys Lufthansa, Malaysia Airlines and Singapore Airlines said soon afterward that they will avoid the region as well.

The FAA previously warned of a risk in the region, but Fridays warning threw into stark relief a danger that both the agency and analysts say is real 7after the shooting down of a Malaysian Airlines flight over Ukraine in 2014. That could further imperil the bottom lines of Gulf long-haul carriers, which already have faced challenges under the Trump administration.

The threat of a civil aircraft shootdown in southern Iran is real, warned OPSGROUP, a company that provides guidance to global airlines.

The FAA made a similar warning in May to commercial airliners of the possibility of Iranian anti-aircraft gunners mistaking them for military aircraft, something dismissed by Tehran some 30 years after the U.S. Navy shot down an Iranian passenger jet.

Iran had no immediate reaction to the U.S. announcement.

The FAA said its warning would affect the area of the Tehran Flight Information Region, without elaborating. The FAAs operations center referred questions to its press office, which did not immediately respond to queries from The Associated Press. However, that likely only extends some 12 miles off of the Iranian coast, aviation experts said.

There are 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 misidentification, the FAA said. The risk to U.S. civil aviation is demonstrated by the Iranian surface-to-air missile shoot-down of a U.S. unmanned aircraft system on 19 June 2019 while it was operating in the vicinity of civil air routes above the Gulf of Oman.