Many reporters, including from the BBC, the Independent and the Guardian have said that they have found no evidence of Hamas forcing Palestinians to stay and become unwilling human shields. The practice has been controversial, as many human rights and news organizations have shown the 'roof knocks' to kill and injure civilians. In July, 2014, Amnesty International called for a United Nations investigation into what it alleged were war crimes committed by Israeli fighters, and Philip Luther, Middle East and North Africa Programme Director for the organization, condemned the practice. The spokesperson for Gaza Health Ministry indicated that the same missiles used to give warnings are also used in assassinations, resulting in dozens of casualties and deaths where "remains were scattered, making it impossible to identify them immediately". The Goldstone Report commented that civilians inside their homes "cannot be expected to know whether a small explosion is a warning of an impending attack or part of an actual attack". It stated that the practice is not an effective advance warning, and is instead likely to "cause terror and confuse the affected civilians". According to the Palestinian Centre for Human Rights, the warning of inhabitants by Israeli forces is psychological warfare, and after the first week of the Operation Cast Lead offensive, only 37 houses had been destroyed despite hundreds of warning calls, while no one can advise people not to take the threats seriously. In other cases, houses in Gaza Strip were bombed without any warning. For example, on July 12, 2014, an Israeli airstrike without any warning on the home of Gaza's police chief, Tayseer Al-Batsh, and a nearby mosque as evening prayers ended, killed 18 civilians, including children, and injured 45 others. The Israeli Government stated "While these warnings, could not eliminate all harm to civilians, they were frequently effective," and that aerial video surveillance by IDF forces showed civilians departing from targeted areas prior to an attack as a direct result of the warnings. According to the Israeli army, striking homes suspected of storing weapons, when sufficient warning is given to the residents, falls within the boundaries of international law and is legitimate. In November 2014, the most senior US military official, General Martin Dempsey, cited "roof knocking" as an example where Israel "did some extraordinary things to limit civilian casualties" during Operation Protective Edge. Amnesty International has reported in a statement that it "does not have evidence at this point" that Palestinian civilians have been intentionally used by Hamas or Palestinian armed groups during the current hostilities to "shield" specific locations or military personnel or equipment from Israeli attacks". It additionally said that "public statements referring to entire areas are not the same as directing specific civilians to remain in their homes as "human shields" for fighters, munitions, or military equipment" and that "even if officials or fighters from Hamas or Palestinian armed groups ... did in fact direct civilians to remain in a specific location in order to shield military objectives ..., all of Israel's obligations to protect these civilians would still apply."