Assailants have killed a senior Saudi security officer whose body was found west of the capital Riyadh, Saudi-owned al-Arabiya television said on Tuesday, in an attack claimed by the terrorist Daesh group.Arabiya identified the officer as Colonel Kitab al-Hammadi and said his body was found in an area called al-Dawami. Daesh's Amaq news website identified Hammadi as the director of internal security in the al-Quwayiyah region.