They thought the packet contained a bomb but it was a false alarm.

他们以为包裹里面装有炸弹，结果是虚惊一场。

Tipstaff surrounded the two pilots who were arrested to cross-question for about 2 hours;finally, it would be found that's false alarm.

当飞机安全降落后，执法人员将两名驾机人围住，并对他们进将近两小时的盘问后，才弄明白这是一场虚惊。