World Central Kitchen has rejected as lacking credibility the findings of an Israeli investigation led by a former general into a coordinated series of Israeli drone strikes on the charity’s vehicles in Gaza this week that killed seven aid workers. As the Israel Defense Forces blamed a series of “grave errors” by officers for the deadly attack that killed three Britons, three other foreign nationals and a Palestinian colleague while delivering food, WCK renewed its calls for a full and independent investigation. Amid mounting international pressure on Israel, the British foreign secretary, David Cameron, said the findings of the Israeli inquiry – which he said the UK was reviewing carefully – showed that “major reform” was required. “It’s clear major reform of Israel’s deconfliction mechanism is badly needed to ensure the safety of aid workers,” Cameron said on X. The hurriedly completed inquiry, which led to two middle-ranking officers being dismissed and a general reprimanded, outlined a catalogue of failings by Israeli forces in an incident that has reinforced global criticism of Israel’s conduct of a war in which 33,000 Palestinians have been killed in six months. While welcoming the report as a first step, WCK’s founder, the celebrity chef José Andrés, said: “The IDF cannot credibly investigate its own failure in Gaza. It’s not enough to simply try to avoid further humanitarian deaths, which have now approached close to 200. All civilians need to be protected, and all innocent people in Gaza need to be fed and safe. And all hostages must be released.” The charity’s chief executive, Erin Gore, said: “Their apologies for the outrageous killing of our colleagues represent cold comfort. It’s cold comfort for the victims’ families and WCK’s global family. Israel needs to take concrete steps to assure the safety of humanitarian aid workers. Our operations remain suspended.” WCK’s remarks were echoed by the UN secretary general, António Guterres, who said fixing failings in Israel’s military procedures required “independent investigations” and meaningful and measurable changes on the ground. Noting that 196 humanitarian workers had been killed during Israel’s campaign, Guterres said: “We want to know why.” The announcement of punishments and the apology have not calmed the international outcry over the WCK workers’ deaths or reassured international aid groups that it is safe to resume operations in Gaza, where nearly a third of the population is on the brink of starvation. The US secretary of state, Antony Blinken, said the US was reviewing the findings and would be looking very carefully at what concrete measures Israel was taking to reduce civilian harm. “It’s very important that Israel is taking full responsibility for this incident. It’s also important that it appears to be taking steps to hold those responsible accountable,” he said in Brussels. “Even more important is that steps are being taken going forward to ensure that something like this can never happen again.” The Israeli military commission of inquiry blamed a series of “grave errors” by military personnel, including lack of coordination and misidentification. The IDF said it had dismissed a brigade chief of staff with the rank of colonel and a brigade fire support officer with the rank of major, and issued formal reprimands to senior officers including the general at the head of the southern command. The rapidly completed investigation failed to resolve key questions including why soldiers from the Nahal brigade responsible were unaware that humanitarian vehicles were operating in the area with IDF permission, and why commanders launched an attack that the IDF said was in flagrant breach of its operational rules. The findings are likely to renew scepticism over the military’s decision-making. Palestinians, aid groups and human rights organisations have repeatedly accused Israeli forces of firing recklessly at civilians throughout the conflict – a charge Israel denies. Among those questioning whether the report was sufficiently thorough was Charlie Herbert, a retired British general who has been a trenchant critic of Israel’s operations during the current conflict. “Two quite junior officers dismissed,” Herbert tweeted. “Presumably for very bad judgment, with tragic consequences. But the real issue here is an institutional one with IDF rules of engagement and disregard for ‘collateral damage’. This is the reason for huge civilian casualties since October.” Scott Paul, of Oxfam, said in a briefing with other relief organisations on Thursday before the results of Israel’s investigation were released: “Let’s be very clear. This is tragic but it is not an anomaly. The killing of aid workers in Gaza has been systemic.” The Israeli military said the investigation found that the officers mishandled critical information and violated the army’s rules of engagement. “The strike on the aid vehicles is a grave mistake stemming from a serious failure due to a mistaken identification, errors in decision-making, and an attack contrary to the standard operating procedures,” it said. The investigation determined that a colonel had authorised the series of drone strikes on the convoy based on one major’s observation – from grainy drone-camera footage – that someone in the convoy was armed. The observation turned out to be untrue. It criticised officers for failing to read messages alerting troops that cars, not aid trucks, would carry workers from the charity away from the warehouse where aid was distributed. As a result, the targeted cars were misidentified as transporting militants. The army also faulted a major who identified the strike target and a colonel who approved the strike for acting with insufficient information. The army said it initially hit one car. As people scrambled away into a second car, it hit that vehicle as well. A third strike was launched as survivors scrambled into a third car. The IDF was unable to say exactly where communication had broken down about the convoy’s plans and declined to answer questions about whether similar violations of rules of engagement had taken place during the war.