Israel has said it was targeting a "Hamas gunman" when it killed seven Gaza aid workers, with the Israeli military admitting a series of "grave mistakes".
In Monday's incident which sparked an international outcry, the victims were killed in three air strikes over four minutes by an Israeli drone as they ran for their lives between their three vehicles, the military said.
The Israel Defence Forces said two senior officers had been dismissed and other commanders had been reprimanded.
In a statement, the IDF said it identified two gunmen on aid trucks during an operation to transfer humanitarian aid from World Central Kitchen in Gaza.
It said that after the WCK vehicles left the warehouse, where the aid had been unloaded, a commander "mistakenly assumed that the gunmen were located inside the accompanying vehicles and that these were Hamas terrorists".
The IDF said its forces did not identify the vehicles as being associated with WCK and "following a misidentification by the forces, the forces targeted the three WCK vehicles based on the misclassification of the event and misidentification of the vehicles as having Hamas operatives inside them, with the result strike leading to the deaths of seven innocent humanitarian aid workers".
The IDF said the incident should not have occurred.
It said the investigation's findings indicated that "those who approved the strike were convinced they were targeting armed Hamas operatives and not WCK employees".
"The strike on the aid vehicles is a grave mistake from a serious failure due to a mistaken identification, errors in decision-making, and an attack contrary to the Standard Operating Procedures," the IDF said.
Senior Israeli officers showed reporters' clips from drone footage of what they said was a "Hamas operative" joining the US-based World Central Kitchen (WCK) convoy.
Although the roofs of the three aid workers' vehicles were emblazoned with large WCK logos, retired Israeli general Yoav Har-Even, who is leading the investigation, said the drone's camera could not see them in the dark.
"This was a key factor in the chain of events," he said.
The aid group has said its team was travelling in a "de-conflicted" area in a convoy of "two armoured cars branded with the WCK logo and a soft skin vehicle" at the time of the strike.
"Despite coordinating movements with the (Israeli army), the convoy was hit as it was leaving the Deir al-Balah warehouse, where the team had unloaded more than 100 tons of humanitarian food aid brought to Gaza on the maritime route," WCK said.
The army said aid was moved at night to avoid the potential of deadly stampedes by hungry Gazans.
WCK demands independent commission, says IDF cannot investigate its own 'failure'
World Central Kitchen has demanded an independent commission to investigate the killings of its staff, saying the Israeli military could not credibly investigate its own "failure".
"Without systemic change, there will be more military failures, more apologies and more grieving families," according to a statement published by WCK.
WCK founder and celebrity chef Jose Andres said the Israeli attack had targeted his workers
"systematically, car by car".
The US and Israel's other allies called for an explanation into the incident, amid widespread condemnation.
WCK said the action taken by Israel following its investigation represented "important steps ahead" but said it is also clear from the preliminary investigation that the Israeli military has deployed deadly force without regard to its own protocols, chain of command and rules of engagement.
Poland says Israel apologised after Polish aid worker killed in Gaza
Poland said that Israel's ambassador had apologised over the death of Pole Damian Sobol in Monday's strike.
"I handed over a note of protest to the ambassador. The ambassador apologised for this event, which has no precedent in the history of the civilised world," Polish Deputy Foreign Minister Andrzej Szejna told a press conference.
Mr Szejna had said Israel's disciplinary measures would not be enough. The ambassador informed him that Israel's top court would conduct a criminal investigation, and Poland wants its prosecutors to take part.
"There should be an investigation under the supervision of the victims' countries under criminal law into this event, which bears the hallmarks of murder," he said, adding that Mr Sobol's family should also be offered compensation.
"The information we received so far (from Israel) is not satisfactory but we see this meeting as a change of tone."
Ambassador Yacov Livne caused outrage in Poland with a social media post on Tuesday that the "extreme right and left" in Poland were accusing Israel of intentional murder, adding that "anti-Semites will always remain anti-Semites".
Mr Szejna said the ambassador would not be expelled.
