A crush at an aid centre in southern Gaza killed at least 20 people Wednesday, with the site's operator blaming "agitators" within the crowd and the Palestinian territory's civil defence agency attributing the panic to Israeli gunfire.

It was the first time that the Gaza Humanitarian Foundation (GHF), backed by the United States and Israel, acknowledged deaths at one of its distribution sites after weeks of chaotic scenes and near-daily reports of Palestinians being killed nearby while waiting to collect rations.

AFP footage showed lifeless bodies taken to a nearby hospital, in the city of Khan Younis, with some placed on the floor and others on already-bloodied beds.

Abdullah Alian, a witness, said that mayhem unfolded as the crowd of aid-seekers was hit with stun grenades and pepper spray.

The latest deaths came as indirect negotiations between Israel and Palestinian resistance group Hamas were ongoing in Qatar, aiming to seal a deal for a 60-day ceasefire, the release of hostages held in Gaza and the unfettered flow of much-needed aid into the territory.

Hamas has accused Israel of wanting to retain long-term military control of Gaza -- a key sticking point in the talks, which are now in their second week in Doha.

Gaza's civil defence agency spokesman Mahmud Bassal said that thousands had gathered at the site when "Israeli forces opened fire and used (tear) gas, causing panic and a stampede after aid centre guards closed the main gates in front of the hungry crowd".

On Tuesday, the UN said it had recorded 875 people killed in Gaza while trying to get food since late May, including 674 "in the vicinity of GHF sites".

In the truce negotiations, Hamas is seeking a full Israeli withdrawal from Gaza, and last week rejected an Israeli proposal that it said would have kept troops in more than 40% of the territory.

Israeli public broadcaster Kan reported Wednesday that work was ongoing to revise Israeli pullback maps, citing an unnamed foreign official.

Bassem Naim, a member of Hamas's political leadership, told AFP that Israel "has not yet delivered any new or revised maps regarding military withdrawals".

Speaking in Gaza Wednesday, Israel's army chief Eyal Zamir said that "in the coming days, we will know whether or not we have an agreement", according to a military statement.

A Palestinian source close to the negotiations earlier told AFP there had been "no progress so far".

If a deal is not reached, Israel will "intensify and expand combat operations as much as possible, beyond what we are currently doing", Zamir said.

Israel, which wants Hamas neutralised as a fighting force, has accused the group of inflexibility but on Tuesday mediator Qatar said there was "no stalemate" and no set timeframe for the talks.

The ongoing ceasefire talks, which started on July 6 are being brokered by mediators Egypt and Qatar with the backing of the United States.