DUBAI, United Arab Emirates (AP) — 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.

Two US Navy pilots ejected safely after their fighter jet was shot down over the Red Sea on Saturday in an apparent friendly fire incident, US Central Command said in a statement.

Two US Navy pilots were shot down by their fellow soldiers following a ‘friendly fire’ incident in the Red Sea. The pilots were shot down accidentally over the Red Sea on Sunday in an area where the US troops have been stationed to target Houthi rebels in Yemen.