‘Roof knocking’: how Israel warns of airstrikes

Controversial early-warning system deployed during strikes on Gaza

A huge explosion in Gaza following an early morning Israeli airstrike
(Image credit: SAID KHATIB/AFP/Getty Images)

Benjamin Netanyahu has pledged to continue bombing Gaza following the death of a father and daughter caused by a rocket launched by Hamas into Israel.

“Since yesterday the army has carried out hundreds of attacks against Hamas and Islamic Jihad in Gaza,” the Israeli prime minister said in a video released by his office. “We will further intensify the power of our attacks”, he continued, adding that Hamas will be targeted “in ways it did not expect”.

Israeli bombing of the Palestinian-held territory has so far killed at least 40 Palestinians – placing the military’s controversial method for warning of impending strikes under the spotlight.

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What is ‘roof knocking’?

Israel fires “warning rockets” – often sent from drones – to alert residents that a building is to be targeted. The Israel Defense Forces (IDF) call the technique “roof knocking”, The Washington Post says, and claim it is a “time-tested strategy”.

The warning rocket has no warhead, and is meant only to shake the building before armed missiles hit it three to 15 minutes later. The Israeli military has deployed the tactic during its bombing of Gaza in recent days, including its strike on a 13-storey residential building in Gaza City.

Palestinians living in the building “received several warnings, including phone calls and messages” informing them of the imminent strike, The Times of Israel reports, before “a preliminary roof-knocking strike” was delivered.

Gaza director of the United Nations Relief and Works Agency, Matthias Schmale, yesterday tweeted: “Residents of a building near my Gaza apartment have been warned it will be taken down and have evacuated. Over the last minutes a number of terrifying loud warning strikes and just now the big one taking it down.”

Israel said it was targeting the site as it housed “an office that is used by the political leadership” of Hamas, Reuters reports. It “was not immediately clear if the building had been fully evacuated, or if there were casualties”, eyewitnesses told the news agency.

Do warnings work?

Middle East and North Africa Research and Advocacy Director at Amnesty International Philip Luther has previously condemned the “roof-knocking” tactic as dangerous and ineffective.

“There is no way that firing a missile at a civilian home can constitute an effective ‘warning’.” Luther said in a 2014 statement. “Amnesty International has documented cases of civilians killed or injured by such missiles in previous Israeli military operations on the Gaza Strip.”

“Unless the Israeli authorities can provide specific information to show how a home is being used to make an effective contribution to military actions, deliberately attacking civilian homes constitutes a war crime and also amounts to collective punishment against the families,” he added.

Why warn before an attack?

Israel uses warning tactics to “avoid charges of indiscriminate killings or even of crimes against the rules of war”, The New York Times says. However, people often “die in any case, because they ignore or defy the warnings, or try to leave after it is too late”.

Bombs often “do not hit the building at which they are aimed”, the paper adds, leading groups such as Human Rights Watch to argue “that Israel’s efforts to warn civilians about impending attacks “do not absolve the armed forces”.

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