They were referring to an earlier round of Pakistani airstrikes carried out less than a week ago - on the night of 21 February - targeting the eastern Nangarhar and Paktika provinces. The United Nations has said it has credible reports that 13 Afghan civilians were killed in those strikes.
// 步骤3：计算初始无序区间[left, right]的最大值和最小值
，更多细节参见同城约会
（二）在铁路、城市轨道交通线路上放置障碍物，或者故意向列车投掷物品的；
Source: Computational Materials Science, Volume 267