The founder of World Central Kitchen (WCK) has accused Israel of targeting his aid workers “systematically, car by car” during the strikes that left seven dead on Monday, as mounting international fury over the attack further strains Western support for Israel’s war in Gaza.

WCK challenged Israel’s response to the attacks in a fresh statement on Thursday and called for an independent inquiry into the strikes, which hit three WCK cars in central Gaza.

“Israel has admitted to the killings but called it a ‘a tragic event in which our forces unintentionally harmed non-combatants,’ and something that ‘happens in war,’” the non-governmental organization said.

“This was a military attack that involved multiple strikes and targeted three WCK vehicles. All three vehicles were carrying civilians; they were marked as WCK vehicles; and their movements were in full compliance with Israeli authorities, who were aware of their itinerary, route, and humanitarian mission,” it added.

Seven people – three Britons, a Palestinian, a US-Canadian dual citizen, an Australian and a Pole – were killed in the strikes, setting off fury in those countries and sparking even greater scrutiny of Israel’s conduct in Gaza since it launched its war against Hamas in October.

In a Reuters interview, the celebrity chef Jose Andres – who founded WCK in 2010 – accused Israel of “systematically” targeting the seven WCK aid workers. This was not a “bad luck situation where, ‘oops,’ we dropped the bomb in the wrong place,” Andres told Reuters.

“Even if we were not in coordination with the (Israel Defense Forces), no democratic country and no military can be targeting civilians and humanitarians.”

WCK urged the governments of those killed to press for an inquiry, and said they have asked the Israeli government “to immediately preserve all documents, communications, video and/or audio recordings, and any other materials potentially relevant” to the strikes in order to “ensure the integrity” of an investigation.

The chief of staff of the Israeli military, Lt. Gen. Herzi Halevi, previously apologized for the strike and described it as “a mistake that followed a misidentification.”

“I want to be very clear – the strike was not carried out with the intention of harming WCK aid workers. It was a mistake that followed a misidentification – at night during a war in very complex conditions. It shouldn’t have happened,” Halevi said.

But Israel’s response to the attack has exacerbated the anger in the home nations of the seven workers killed.

Australia’s Prime Minister Anthony Albanese said Thursday that Israel’s explanation for the strikes was “not good enough.”

“We need to have accountability for how it’s occurred. And what isn’t good enough are the statements that have been made, including that this is just a product of war,” he said. “This is against humanitarian law.”

Poland’s Prime Minister and President have both said Israel owes compensation to the family of Polish victim Damian Sobol.

A diplomatic row meanwhile erupted in Warsaw after Israeli ambassador Yacov Livne wrote on X that Poland’s “extreme right and left” were accusing Israel of intentional murder, adding: “Anti-Semites will always remain anti-Semites.” Those comments were labelled “outrageous” by Poland’s President Andrzej Duda, and deepened a rift between Poland and Israel since Sobol’s death.

But many eyes around the world were on the response of the United States, Israel’s most important ally and a supplier of a significant amount of arms and military aid.

‘Unacceptable’

US President Joe Biden called the deaths of aid workers and the overall humanitarian situation in Gaza “unacceptable” in a call with Netanyahu on Thursday, adding that US support would depend on “measurable steps to address civilian harm, humanitarian suffering, and the safety of aid workers.”

“He made clear that U.S. policy with respect to Gaza will be determined by our assessment of Israel’s immediate action on these steps,” the White House said shortly after the end of the call.

In the aftermath of the deaths, a senior officials said Biden was “angry” and “increasingly frustrated,” and fully prepared to make all of that known to Netanyahu in their conversation. “He will express those frustrations,” the official said.

A CNN analysis of aftermath videos and images found that the attack appears to have consisted of multiple precision strikes.

CNN geolocated video and imagery of all three destroyed vehicles, at least one of which was clearly marked with a WCK logo on its roof, to two positions on the strip’s Al Rashid coastal road, and a third location on an off-road area of open ground nearby. The first location was around 2.4 kilometers from the third, indicating that the three vehicles were hit by separate strikes.

Israel has only committed to an internal investigation into the events, the results of which are expected “in the coming weeks,” Israeli government spokesperson Raquela Karamson said Thursday.

In addition to touching off anger around the world, the strikes have caused concern that the distribution of food aid in Gaza – which was already extremely limited – will become even more dangerous.

A WCK-linked boat carrying roughly 332 tons of humanitarian aid left Gaza without offloading most of its cargo following the deadly Israeli military strike, according to the Cypriot foreign ministry.

Hundreds of humanitarian workers have been killed during Israel’s war with Gaza – alongside more than 33,000 Palestinians, according to latest figures from the health ministry in the enclave.