The Israeli army on Friday admitted a series of errors and violations of its rules in the killing of seven aid workers in Gaza, saying it had mistakenly believed it was "targeting armed Hamas operatives."

The two brigade officers who ordered the drone strikes, a colonel and a major, have been fired, the army said, and its Southern Command chief reprimanded.

It was a rare confession of wrongdoing by Israel in its nearly six-month war against Hamas militants in the Gaza Strip, where the health ministry of the Hamas-ruled territory says more than 33,000 people, mostly civilians, have been killed.

The victims – an Australian, three Britons, a North American, a Palestinian and a Pole – were killed on Monday night in three strikes over four minutes by an Israeli drone as they ran for their lives between their three vehicles, the military said.

The US-based charity for which they worked, World Central Kitchen, demanded an independent inquiry, and Poland called for a "criminal" probe after the military's announcement.

The drone team who killed the aid workers made an "operational misjudgement of the situation" after spotting a suspected Hamas gunman shooting from the top of one of the food trucks the aid workers were escorting, an internal Israeli military inquiry found.

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 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 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," WCK said.

The army said aid was moved at night to avoid deadly stampedes by hungry Gazans.

The aid workers' deaths "outraged" US President Joe Biden who demanded Israeli Prime Minister Benjamin Netanyahu order steps toward an "immediate ceasefire."

Israel later said it would allow "temporary" aid deliveries into northern Gaza, where the United Nations has warned of imminent famine.

Har-Even admitted that "the three air strikes were in violation of standard operating procedures." (AFP)