Israel's defence chief said Wednesday a strike that killed seven aid workers in Gaza was a "grave mistake", after the deaths prompted a chorus of international outrage.

"This incident was a grave mistake," IDF chief Herzi Halevi said in a video message after the strike that hit a World Central Kitchen (WCK) convoy delivering aid on Monday.

"It shouldn't have happened," Halevi said, as he blamed the strike on a nightime "misidentification".

"We are sorry for the unintentional harm to the members of WCK."

AFPTV footage from the scene showed the punctured roof of a vehicle emblazoned with WCK's logo alongside the mangled wreck of other vehicles.

Since the October start of the war, the US-based charity had been involved in feeding displaced Gazans, and was one of two organisations spearheading the delivery of food aid arriving by sea.

The employees killed on Monday had just unloaded "more than 100 tons of humanitarian food aid brought to Gaza on the maritime route," WCK said.

The attack, which killed Australian, British, Palestinian, Polish and US-Canadian staff, was widely condemned, with world leaders demanding an investigation.

In a strongly worded statement, US President Joe Biden said Israel "has not done enough to protect aid workers trying to deliver desperately needed help to civilians."

He called for a "swift" investigation to bring accountability to what he said was not a "stand alone incident".

UN Secretary-General Antonio Guterres told the General Assembly that 196 humanitarian workers have been killed in the war.

He called the strike "unconscionable" but "an inevitable result of the way the war is being conducted".

"It demonstrates yet again the urgent need for an immediate humanitarian ceasefire."

- 'Anger and concern' -

WCK said it was mourning the loss of its seven "heroes", naming them on Wednesday as Palestinian Saifeddine Issam Ayad Abutaha, 25; Australian Lalzawmi (Zomi) Frankcom, 43; Pole Damian Sobol, 35; American-Canadian Jacob Flickinger, 33; and Brits John Chapman, 57, James (Jim) Henderson, 33, and James Kirby, 47.

"These 7 beautiful souls were killed by the IDF in a strike as they were returning from a full day's mission," WCK CEO Erin Gore said.

The organisation called the strike a "targeted attack" and said its team had been coordinating its movements with the Israeli forces.

"This is not only an attack against WCK, this is an attack on humanitarian organizations showing up in the most dire of situations where food is being used as a weapon of war," Gore said in an earlier statement.

Gaza has been under Israeli blockade since the start of the war, with the United Nations accusing Israel of preventing humanitarian aid deliveries and warning of "catastrophic" hunger.

World Central Kitchen was facilitating the provision of supplies brought by sea from Cyprus.

Following the strike, it said it was suspending its operations in the region, deepening concerns about how urgently needed food aid will reach a starving population.

Cyprus said on Tuesday that the aid ship the Jennifer was returning to the Mediterranean island with around 240 tonnes of supplies that had not been unloaded.

Israeli Prime Minister Benjamin Netanyahu said the military had "unintentionally" killed the aid workers, calling it a "tragic case" that would be investigated "right to the end".

He did not, however, apologise.

Australian Prime Minister Anthony Albanese said he spoke to Netanyahu by phone, raising his "anger and concern".

Britain summoned the Israeli ambassador to London and demanded "full accountability".

And Poland demanded compensation for the families of the killed aid workers.

The bodies of the six foreign aid workers were to be sent to Gaza's southern border on Wednesday before being repatriated, according to Marwan al Hams, the director of a hospital in the territory's southern city Rafah.

- 'Traitor' -

The aid workers' deaths come as relentless Israeli strikes continue to pound the territory, flattening critical infrastructure, all but collapsing the health system and pushing more than half the population to the brink of famine.

Overnight, Israeli strikes killed at least 60 people, the health ministry in Hamas-run Gaza said Wednesday.

Regional tensions have also surged after Israel was blamed for an air strike on the consular annex of the Iranian embassy in Syria's capital Damascus on Monday that killed seven Revolutionary Guards, two of them generals.

Tehran, which backs Hamas and other groups fighting Israel and its allies across the region, has vowed revenge.

Netanyahu has promised to push on with the war to destroy Hamas despite nightly protests demanding he step down.

The bloodiest-ever Gaza war erupted with Hamas's October 7 attack, which resulted in about 1,160 deaths in Israel, mostly civilians, according to an AFP tally of Israeli official figures.

Israel's retaliatory campaign has killed at least 32,916 people, mostly women and children, according to the health ministry in Hamas-run Gaza.

During their attack on Israel, Palestinian militants also seized around 250 hostages. Israel believes about 130 remain in Gaza, including 34 who are presumed dead.

The families of the Israeli hostages have blasted Netanyahu and staged four consecutive nights of protests.

Thousands gathered in front of the country's parliament Tuesday, with former prime minister Ehud Barak blaming Netanyahu for the October 7 "disaster" and demanding an election.

Einav Zangauker, whose son Matan is still held in Gaza, accused Netanyahu of trying to blacken the reputation of the hostage families.

"You call us traitors when you are the traitor, a traitor to your people, to the State of Israel," Zangauker said.

The Palestinians, meanwhile, have revived their application to become a full member state in the United Nations.

In a letter to UN chief Guterres that was seen by AFP, Palestinian UN envoy Riyad Mansour requested "upon instructions of the Palestinian leadership" that an application dating back to 2011 be reconsidered this month by the Security Council.