SANAA, Yemen (AP) — Yemen’s rebels fired three ballistic missiles Sunday at a government-held central city, killing two children and wounding more than 30 people, officials said. The attack was the latest by the Iranian-backed Houthi rebels on Marib, as they have for months been trying to retake the energy-rich city from the internationally recognized government of exiled President Abed Rabbo Mansour Hadi.