The Federal Aviation Administration has ordered U.S. airlines to avoid Iranian airspace as tensions escalate between Washington and Tehran after a $130 million military done was shot down over the Gulf of Oman.

Heightened military activities in the region “present an inadvertent risk to U.S. civil aviation operations and potential for miscalculation or misidentification,” when flying above waterways in the area, the FAA said. “The risk to U.S. civil aviation operation is demonstrated by the Iranian surface-to-air missile shoot-down of a U.S. unmanned aircraft.”