As an escalation of the Yemeni Civil War, starting on 26 March 2015, Saudi Arabia, the United Arab Emirates, and several other regional allies started a military operation in Yemen. Both the Saudi Army Aviation and the United Arab Emirates Air Force used their AH-64 Apache helicopters in combat against an alliance between elements of the Yemeni Army loyal to the former president Saleh and the Houthis. The Apaches were mostly involved in border patrol and strikes in North Western Yemen. Over the years, several Saudi and an Emirati AH-64 Apache helicopters were lost to incidents and enemy fire, although exact numbers have not been independently confirmed.