 The security detail moved to establish a perimeter around the embassy compound and the Air Force 's AC @-@ 130 arrived to provide overhead support . Ambassador Bishop gave the security detail clear instructions on the rules of engagement : they could only use deadly force if people came over the embassy compound 's walls with obvious hostile intent . He also identified three zones of defense , stating a preference to retreat to the third zone before the use of deadly force : 
 The security detail<a href='been_done' title='1'><mark></mark></a> moved to establish a perimeter around the embassy compound and the Air Force <a href='null_genetive' title='2'><mark>'s</mark></a>AC @-@ 130 arrived to provide overhead support . Ambassador Bishop gave the security detail clear instructions on the rules of engagement : they could only use deadly force if people came over the embassy compound <a href='null_genetive' title='3'><mark>'s</mark></a>walls with obvious hostile intent . He also identified three zones of defense , stating a preference to retreat to the third zone before the use of deadly force : 
Da security detail done moved to establish a perimeter around tdaembassy compound and the Air Force  AC @-@ 130 arrived to provide overhead support . Ambassador Bishop gave the security detail clear instructions on the rules of engagement : they could only use deadly force if people came over the embassy compound  walls with obvious hostile intent . He also identified three zones of defense , stating a preference to retreat to thdahird zone before the use of deadly force :