![Pakistani troops arrive at the Pakistan military air base after an attack by militants in southern Pakistan's Karachi on May 23, 2011. At least four people were killed and one plane was destroyed following attacks launched by terrorists late Sunday night at a Pakistan air base in Karachi. [Toheed/Xinhua]](http://images.china.cn/attachement/jpg/site1007/20110523/001fd04cf34a0f44184958.jpg "Pakistani troops arrive at the Pakistan military air base after an attack by militants in southern Pakistan's Karachi on May 23, 2011. At least four people were killed and one plane was destroyed following attacks launched by terrorists late Sunday night at a Pakistan air base in Karachi. [Toheed/Xinhua]")
Pakistani troops arrive at the Pakistan military air base after an attack by militants in southern Pakistan's Karachi on May 23, 2011. At least four people were killed and one plane was destroyed following attacks launched by terrorists late Sunday night at a Pakistan air base in Karachi. [Toheed/Xinhua]