DUBAI, United Arab Emirates — Two U.S. Navy pilots were shot down Sunday over the Red Sea in an apparent “friendly fire” incident, the U.S military said, marking the most serious incident to threaten troops in over a year of America targeting Yemen’s Houthi rebels.

An F/A-18 fighter jet was "mistakenly fired on" by the guided missile cruiser USS Gettysburg, authorities said.

A U.S. Navy ship mistakenly shot down an American fighter jet over the Red Sea early Sunday, the U.S. military said, highlighting the potential risks for international forces as they try to stop attacks on cargo ships by the Houthi militia in Yemen.