Twenty people trying to get food have been killed “amid a chaotic and dangerous surge” at an aid distribution centre in southern Gaza, the US- and Israel-backed Gaza Humanitarian Foundation (GHF) says.

Nineteen were trampled to death and one was stabbed in the “tragic incident” at the GHF’s site in the Khan Younis area, a statement said, adding that it believed the surge was “driven by agitators in the crowd” who were affiliated to Hamas.

It was not immediately possible to verify the report.

However, Nasser Hospital in Khan Younis earlier said it had received the bodies of 10 people who were killed due to “suffocation” after an aid site was closed by the GHF’s US private security contractors.

There have been almost daily reports of Palestinians being killed while seeking aid since the GHF began operations in late May. Witnesses say most have been shot by Israeli forces.

The UN human rights office said on Tuesday that it had so far recorded 674 killings in the vicinity of the GHF’s four sites in southern and central Gaza over the past six weeks. Another 201 killings had been recorded along routes of UN and other aid convoys, it added.

Before Wednesday, the GHF had denied that there had been any deadly incidents in close proximity to its sites and accused the UN of using “false and misleading” figures from Gaza’s Hamas-run health ministry.

The Israeli military said last week that it recognised there had been incidents in which civilians had been harmed and that it was working to minimise “possible friction between the population and the [Israeli] forces as much as possible”.

The GHF uses private security contractors to distribute aid from sites in Israeli military zones.

The UN refuses to co-operate with it, describing its set up as unethical.