That is another tactic how to get the Hamas people. Everyone will try to get out the building after Israel's warning include Hamas people. (Who want to stay in the building and wait for the bombing?) It is a lot easier for Israel to track the Hamas people while they are out of the building and try to kill them by using drones.
警告：大楼内有哈马斯人员藏身 你有十分钟撤离