World Central Kitchen demanded an independent investigation into the Israeli strikes that killed seven of its staff in Gaza, as Israel faced growing isolation Wednesday over the deaths of six foreign aid workers and a Palestinian driver helping deliver desperately needed food to isolated and starving residents.

Wednesday night, U.S. Defense Secretary Lloyd Austin told his Israeli counterpart that the strikes, which Israel says targeted the aid workers in error, strengthened U.S. concerns about Israel’s plans to expand its ground offensive and said that Israel must do more to protect the lives of civilians and aid workers in Gaza.

Israel’s war in Gaza has killed nearly 33,000 Palestinians, the territory’s Health Ministry says. The ministry doesn’t differentiate between civilians and combatants in its tally, but says women and children make up two-thirds of the dead. The United Nations says much of the population in northern Gaza is on the brink of starvation.

Israel Defense Forces Chief General Staff Herzi Halevi has said the attack on the World Central Kitchen vehicle was not intentional and should not have happened.

“It was a mistake that followed a misidentification at night, during a war, in very complex conditions,” he said in a recorded statement.

Prime Minister Benjamin Netanyahu also said Israel will conduct a review of the event and has been in contact with the governments of the deceased workers.

“Unfortunately, in the past day there was a tragic event in which our forces unintentionally harmed non-combatants in the Gaza Strip. This happens in war,” he said.

In the tersely worded statement, the World Central Kitchen executives dismissed the explanations coming from Israel, stating the military attack involved multiple strikes targeting three of its 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,” Garcia and Gore said.

The pair of executives said they have asked Australia, Britain, Canada, Poland and the United States to join their demand for an independent investigation.

On Wednesday, the charity had called on Israel to preserve all documents, communications and video as well as other material related to Monday’s strike to ensure the integrity of the investigation.

In Washington, State Department spokesman Matthew Miller told reporters during a press briefing that they expect Israel to conduct a full, swift and transparent investigation into the strike and if it shows the need for accountability, “then there, of course, should be accountability.”

“We will wait to see the results of that investigation before we pass judgment on it,” he said.

“The Israelis have said to us, and they’ve said publicly, that they intend to conduct this investigation swiftly. We want to see it wrapped up as soon as possible and see them put in place any measures to prevent this from happening again in the future.”

Founded in 2010 by chef Jose Andres, the charity has served more than 34 million meals in Gaza, Israel and Lebanon since Oct. 7 when the war between Israel and Hamas in the Palestinian enclave began.

UPI and The Associated Press