African Union chief Moussa Faki Mahamat on Saturday accused Israel of "the mass killing of Palestinians" and urged an international probe after dozens died following a rush on an aid convoy in war-torn Gaza.

"Mahamat strongly condemns an attack by Israeli forces, that killed and wounded more than 100 Palestinians seeking life-saving humanitarian aid," the bloc said in a statement dated Friday but posted on X on Saturday.

"The Chairperson calls for an international investigation into the incident to bring the perpetrators to account," the statement said, urging "an immediate and unconditional ceasefire".

Israeli troops opened fire as Palestinian civilians scrambled for food supplies during a chaotic melee on Thursday that the Hamas-run territory's health ministry said killed more than 100 people in Gaza City.

The deaths came after a World Food Programme official had warned: "If nothing changes, a famine is imminent in northern Gaza."

The Israeli military said a "stampede" occurred when thousands of Gazans surrounded the convoy of 38 aid trucks, leading to dozens of deaths and injuries, including some who were run over.

An Israeli source acknowledged troops had opened fire on the crowd, believing it "posed a threat".

Gaza's health ministry called it a "massacre", and said 115 people were killed and more than 750 wounded.

World leaders have called for an investigation, with President Joe Biden saying Friday that the United States would start delivering relief supplies into Gaza via air drops -- as some of its allies have already -- in a bid to get aid into hard-to-reach areas.

The aid convoy deaths helped push the number of Palestinian war dead in Gaza to 30,228, mostly women and children, according to the latest toll from the territory's health ministry.

The war began on October 7 with an unprecedented Hamas attack on southern Israel that resulted in the deaths of about 1,160 people, mostly civilians, Israeli figures show.

Militants also took about 250 hostages on October 7, 130 of whom remain in Gaza, including 31 that Israel says are presumed dead.

Israel's military says 242 soldiers have died in Gaza since ground operations began in late October.