The United Nations on Wednesday condemned a US-backed aid system in Gaza after 47 people were injured during a chaotic food distribution that saw shots fired by the Israeli military.

The issue of aid has come sharply into focus amid a hunger crisis coupled with intense criticism of the Gaza Humanitarian Foundation (GHF), a shadowy group that has bypassed the longstanding UN-led system in the territory.

With the war sparked by Hamas's October 2023 attack on Israel entering its 600th day on Wednesday, Palestinians in Gaza felt there was no reason to hope for a better future.

In Israel, the relatives of people held hostage in Gaza since the October 7, 2023, attack longed for the return of their loved ones, with hundreds gathering in their name in Tel Aviv.

"Six hundred days have passed and nothing has changed. Death continues, and Israeli bombing does not stop," said Bassam Daloul, 40, adding that "even hoping for a ceasefire feels like a dream and a nightmare".

Daloul, who said his family has been displaced 20 times since the start of the war, pointed to shortages of everything from clean water and food to medicine and electricity.

On Tuesday, scenes of desperation and mayhem erupted at a GHF aid distribution centre in southern Gaza, with shots fired by the Israeli military as thousands of Palestinians rushed into the site.

According to the UN, 47 people were injured in the chaos while a Palestinian medical source said at least one had died.

The Israeli military said it fired warning shots, though Ajith Sunghay, the head of UN Human Rights Office in the Palestinian territories, said most of the wounded had been hurt by gunfire.

The UN has repeatedly hit out against the GHF, and Philippe Lazzarini, head of the UN agency for Palestinian refugees, on Wednesday reiterated the criticism.

"I believe it is a waste of resources and a distraction from atrocities. We already have an aid distribution system that is fit for purpose," he said during a visit in Japan. (AFP)