ADEN, Yemen (AP) — Yemeni security and medical officials say a shootout in the south between security forces and southern separatists has killed two pro-independence fighters and wounded 18.

Thursday’s clashes came as Yemenis marked the first anniversary of the election of President Abed Rabbo Mansour Hadi. The election — in a one-candidate referendum vote — was part of U.S.-backed power transfer deal following a year-long uprising that ousted longtime autocratic ruler Ali Abdullah Saleh.