Israel has drawn heat from the international community after more than 100 people were killed as they waited for an aid delivery in the Gaza Strip on Thursday, an incident that Palestinian health authorities blamed on Israeli forces but was attributed by Israel to crowds that surrounded the air trucks.

Shots were fired as hundreds of people gathered around an aid convoy coordinated by Israel to send relief to the Palestinians in Gaza, who are undergoing a humanitarian disaster owning to Israel's months-old bombardment of the coastal enclave since Hamas' deadly rampage in southern Israel on October 7.

Palestinian President Mahmoud Abbas said it was an "ugly massacre" by Israel, and France condemned "unjustifiable Israeli fire" in the scramble for food aid.

United Nations Secretary-General Antonio Guterres's office also issued a statement denouncing the incident, without assigning blame.

At least 112 people were killed and more than 280 wounded in the incident near Gaza City, Palestinian health officials said.

Israel said it was not to blame for the "unfortunate" event. One Israeli official said there had been two incidents, hundreds of meters apart. In the first, dozens were killed or injured as they tried to take aid from the trucks and were trampled or run over, according to the official.

He said there was a second, subsequent incident as the trucks moved off. Some people in the crowd approached troops who felt under threat and opened fire, killing an unknown number in a "limited response," he said. He dismissed the casualty toll given by Gaza authorities but gave no figure himself.

In a rebuttal to the Israeli account, Hamas said the Gaza health ministry had presented "undeniable" evidence of "direct firing at citizens, including headshots aimed at immediate killing, in addition to the testimonies of all witnesses who confirmed being targeted with direct fire without posing any threat to the occupying army."

Jordan's foreign ministry, in a statement following the incident, reiterated its condemnation of Israel's persistent aggression and said its brutal targeting of civilians was a blatant violation of international law.

The Turkish foreign ministry said "Israel has added another crime to its crimes against humanity."

Hamas said the incident could jeopardize talks in Qatar aimed at securing a ceasefire and the release of Israeli hostages it is holding. When asked if he thought it would complicate the talks, U.S. President Joe Biden said: "I know it will."

The U.S. State Department said it was urgently seeking information on the incident, as did the French foreign ministry.

The incident has added more strains to health facilities that are already on the brink of collapse in Gaza. Medics said they could not cope with the flood of serious injuries, which came as the death toll in nearly five months of war passed 30,000, according to Palestinian health authorities.

In a statement on Thursday, UN human rights chief Volker Turk said war crimes had been committed by all parties in the conflict between Israel and Hamas, calling for them to be investigated and for those responsible to be held accountable.

(With input from agencies)