Roof knocking

Roof knocking (Hebrew: הקש בגג‎) or "knocks on the roof" is a term used by the Israel Defense Forces (IDF) to describe its practice of dropping non-explosive or low-yield devices on the roofs of targeted civilian homes in the Palestinian territories as a prior warning of imminent bombing attacks to give the inhabitants time to flee the attack. The practice was employed by the IDF during the 2008–2009 Gaza War, Operation Pillar of Defense in 2012, and Operation Protective Edge in 2014 to target the homes of police officers or Hamas political or military leaders.

As early as 2006 the IDF had the practice of warning the inhabitants of a building that was about to be attacked. Roof knocking was used during the 2008–2009 Gaza War, Operation Pillar of Defense in 2012, and Operation Protective Edge in 2014. In the six months prior to its use, Israel collected data on Hamas members, which they used to issue warnings. Typically, Israeli intelligence officers and Shin Bet security servicemen contacted residents of a building in which they suspected storage of military assets and told them that they had 10–15 minutes to flee the attack, although in some cases the delay has been as little as five minutes.

In 2016 it was published that the US military adopted the Israeli battlefield tactic for the war against ISIS. It was used in an attack against ISIL storage facility in Mosul, Iraq. As women and children lived in the house, a Hellfire missile was shot at the roof as a warning.

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