The statement said the attack was the result of “errors” and was “contrary” to military procedures. It added that two officers would be dismissed and commanders reprimanded but made no mention of legal actions like prosecutions.

World Central Kitchen said in a statement Friday that the findings were an “important step forward” but that the IDF “cannot credibly investigate its own failure in Gaza.”

“We demand the creation of an independent commission to investigate the killings of our WCK colleagues,” it said.

Monday’s attack highlighted the perils facing aid workers navigating the world’s worst humanitarian crisis during Israel’s punishing military offensive in Gaza. More than 200 aid workers have been killed in the conflict, according to the United Nations. Aid groups say they have been attacked despite coordinating their movements or locations with Israeli authorities.

The deaths of the WCK employees and volunteers — six of them foreign nationals, including one American — have prompted, in a matter of days, a reckoning regarding Israel’s military tactics in a way that strikes that have killed thousands of Palestinian civilians over six months have not, human rights groups say.

On Thursday and Friday, the IDF outlined the results of its investigation, first in a briefing with reporters and then in a statement with an accompanying map.

“The investigation’s findings indicate that the incident should not have occurred,” the statement said. “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 a commander “mistakenly” assumed that Hamas gunmen were in the convoy’s vehicles and that Israeli forces also failed to identify the vehicles as belonging to the WCK. In a separate briefing for reporters Thursday, the IDF said the biggest mistake was that the operators of the unmanned aerial vehicle tracking the convoy were not made aware of the aid convoy’s coordination plan.

And although WCK vehicles are marked with the organization’s logo and name on their roofs, that logo was not visible to the cameras tracking the vehicle at night, said Yoav Har-Even, head of the IDF fact-finding and assessment mechanism. He called that a key factor in the failure.

Some of the details by the IDF appeared contradictory. Officials suggested both that the convoy was never identified as belonging to the WCK, but also that the drone operator became convinced that a convoy with a humanitarian mission had been taken over by Hamas.

The IDF said three procedural rules were violated: The official coordination plan was not communicated from the top to the ground; the airstrike targets were confirmed only by seeing an armed man, which it said was an insufficient standard; and the shooting continued from one vehicle to another when the operator saw people running from the first vehicle after it was struck.

According to accounts of the attack, after the first vehicle was hit, passengers fled to the remaining two vehicles, which then moved on before each was hit, one after the other.

In the wake of the attack, Biden told Israeli Prime Minister Benjamin Netanyahu that the United States, Israel’s strongest international backer, would have to reassess its policy toward Israel’s operation in Gaza unless steps were taken to protect aid workers and address the humanitarian situation in the enclave. The warning marked a rare moment when the United States suggested that support for Israel might be something other than unconditional.

Israel afterward announced steps to facilitate more aid deliveries — especially to the north of Gaza, which international organizations have said is at risk of famine — by reopening the Erez crossing into Gaza and using Israel’s Ashdod port for deliveries.

Secretary of State Antony Blinken on Friday welcomed Israel’s announcement on opening further aid routes to Gaza but said Washington will be “looking closely” for progress on improving aid access. He said the U.S. would review the results of Israel’s investigation into the WCK attack “very carefully” and would discuss them with Israeli leaders and aid groups.

The WCK, in its statement, said the IDF acknowledged that the aid group’s teams complied with all proper communications procedures. The Israeli military’s own video of the attack, it added, “fails to show any cause to fire on our personnel convoy, which carried no weapons and posed no threat.” Edited footage was shown to reporters Thursday, but it did not show the moment the convoy was struck. The video has not been released publicly.

The group’s chief executive, Erin Gore, said the IDF’s “apologies for the outrageous killing of our colleagues represent cold comfort.” The group said its operations, which were paused after the attack, remain suspended.

“Without systemic change, there will be more military failures, more apologies and more grieving families,” the WCK statement added.

More than 33,000 Palestinians, the majority of them women and children, have been killed since the start of Israel’s military operations in Gaza, according to the health ministry there. The war started after Hamas militants carried out a brutal cross-border incursion into Israel, killing at least 1,200 people and taking more than 200 hostages.

A report released by Human Rights Watch on Thursday found that at least 106 Palestinian civilians were killed when Israel struck a residential building in central Gaza on Oct. 31 — one of the deadliest single incidents for civilians during the war. The dead included at least 54 children, some of whom were killed playing soccer in the street outside the building, called the Engineers’ Building, according to HRW.

The group said it “found no evidence of a military target in the vicinity of the building at the time of the Israeli attack, making the strike unlawfully indiscriminate under the laws of war.” Israel, which HRW said had a “long track record of failing to credibly investigate alleged war crimes,” had provided no justification for the attack, the group said.

In its statement on the WCK strike Friday, the IDF emphasized its “commitment to fighting against the Hamas terrorist organization, while upholding the values of the IDF, the laws of war, and avoiding harming civilians.”

In a separate investigation, the IDF said Friday that a military helicopter crew had mistakenly killed a hostage when it fired at a vehicle carrying Hamas militants and hostages on Oct. 7.

The hostage, Efrat Katz, was abducted from Nir Oz, a kibbutz, on Oct. 7, the IDF said in a statement. A helicopter crew “fired at a vehicle that had terrorists, and which, in retrospect … also had hostages in it,” it said.

The investigation found that “as long as Israeli hostages were present in the moving vehicle, they could not be distinguished by the existing surveillance systems,” the IDF said. It called the episode “tragic and unfortunate” but said the commander of the air force “did not find fault in the operation by the helicopter crew, who operated in compliance with the orders in a complex reality of war.”

Yasmeen Abutaleb and Bryan Pietsch contributed to this report.