Israel has faced growing condemnation over the humanitarian crisis in the war-ravaged Gaza Strip, where the United Nations has warned the entire population faces the risk of famine after no aid was allowed to enter for more than two months.

Israel recently eased its blockade and introduced a revamped aid mechanism in cooperation with a newly formed US-backed organization, bypassing the longstanding UN-led system.

The organization, the Gaza Humanitarian Foundation (GHF), says it has distributed millions of meals since operations began last week, but the rollout has been marked by chaotic scenes at the limited number of distribution centers.

Civil defense spokesman Mahmud Bassal told AFP that "31 people were killed and more than 176 injured... after Israeli gunfire targeted thousands of civilians near the American aid center in Rafah", in southern Gaza.

AFP images showed Palestinians transporting bodies on donkey carts near the aid point as others carried away boxes and bags of supplies under the early-morning sun.

Abdullah Barbakh, a 58-year-old Palestinian man, described "chaos" at the site.

"The army opened fire from drones and tanks," he said. "I don't understand why they call people to the aid centers and then open fire on them."

Near another GHF aid center in central Gaza, AFP images showed rescuers evacuating injured people. Bassal reported one dead and dozens wounded there, again blaming Israeli fire.

The Israeli military said an initial inquiry found its troops "did not fire at civilians while they were near or within the humanitarian aid distribution site and that reports to this effect are false".

"Hamas does everything in its power to undermine food distribution efforts in the Gaza Strip," it added, urging the media to "be cautious with information published" by the group.

A GHF spokesperson also denied any deaths or injuries took place, adding that "these fake reports have been actively fomented by Hamas".

'Death follows you'

Sameh Hamuda, a displaced 33-year-old from northern Gaza, told AFP he had walked from Gaza City and spent the night with relatives near Rafah before heading to the aid center around 5:00 am to wait among a crowd of people.

"Suddenly quadcopter drones opened fire on the people, and tanks started shooting heavily. Several people were killed right in front of me," he said.

"I ran and survived. Death follows you as long as you're in Gaza."

At Al-Awda hospital in central Gaza, Umm Muhammad Abu Khousa told AFP her son was among those wounded near the other aid center in Bureij.

"You feed me and then you kill me?" she said from her son's bedside.

Victoria Rose -- a British surgeon visiting Nasser Hospital where many of the patients from Rafah were taken -- described in a video message from the facility a scene of "absolute carnage", saying "all the bays are full, and they're all gunshot wounds".

Speaking about the reported deaths to US broadcaster ABC, World Food Programme Executive Director Cindy McCain said "our people are reporting the same thing on the ground".

"It's a tragedy. And what we need right now is an immediate ceasefire, complete, unfettered access... to feed people and stop this catastrophe from happening," she added.

Only limited amounts of aid have entered Gaza since Israel eased its total blockade that began in March.

The UN and the WFP have recently reported looting of some supplies, including by gunmen.

On Friday a spokesman for the UN humanitarian agency called Gaza "the hungriest place on earth".

GHF, which uses contracted US security, said on Sunday that it had distributed more than 4.7 million meals' worth of food so far.

The United Nations and major aid groups have refused to cooperate with the organization, saying it contravened basic humanitarian principles and appeared designed to cater to Israeli military objectives.

Philippe Lazzarini, head of the UN's agency for Palestinian refugees, said on Sunday that Gaza "aid distribution has become a death trap".

"Aid deliveries and distribution must be at scale and safe," he added in a post on X. "In Gaza, this can be done only through the United Nations including UNRWA."

Truce offer

Nearly 20 months into the war, negotiations for a ceasefire and hostage release deal have failed to produce a breakthrough.

Since the last brief truce collapsed in March, Israel has intensified its operations to destroy Hamas, the Palestinian group whose October 7, 2023 attack triggered the war.

Hamas said it had responded positively -- albeit with requested amendments -- to the latest US-backed truce proposal on Saturday, but US envoy Steve Witkoff criticized the reply as "totally unacceptable", an assessment echoed by Israel.

Witkoff urged the group to "accept the framework proposal we put forward".

Qatar and Egypt, which have served as mediators in ceasefire talks throughout the war, emphasized in a joint statement the "importance of intensifying efforts to overcome the obstacles facing the negotiations".

Hamas said it was ready to "immediately begin a round of indirect negotiations to reach an agreement on the points of contention".

Defense Minister Israel Katz, meanwhile, said he had told the army "to continue forward in Gaza against all targets, regardless of any negotiations".

The health ministry in Hamas-run Gaza says at least 4,149 people have been killed in the territory since Israel resumed its offensive on March 18, taking the war's overall toll to 54,418, mostly civilians.

Hamas' 2023 attack on Israel resulted in the deaths of 1,218 people, mostly civilians, according to an AFP tally based on official figures.