CNN  — 

At least 20 people were killed in a crowd crush at an aid distribution site run by the Gaza Humanitarian Foundation (GHF), the controversial Israeli- and US-backed organization said Wednesday, the first time it has acknowledged deaths at one of its sites.

According to the GHF, the people died in a “chaotic and dangerous surge,” which it said was “driven by agitators in the crowd.” The aid group said 19 people were trampled and one person was stabbed in the crowd crush.

The GHF alleged that individuals who were “armed and affiliated with Hamas” deliberately instigated the chaos. “For the first time since operations began, GHF personnel identified multiple firearms in the crowd, one of which was confiscated,” it said.

Hamas’ Government Media Office (GMO) blamed the GHF for the incident, claiming the group called on Palestinians to receive aid at the site in Khan Younis, southern Gaza, then “proceeded to lock the iron gates after herding thousands of starving people into narrow iron corridors.”

The Palestinian health ministry said 21 people were killed in the incident, 15 of whom died from suffocation after tear gas was fired at a crowd of people awaiting aid, triggering a crowd crush.

One eyewitness, Yahya Al Sousi, told CNN that he was “running to get aid” when “the Americans closed the gates in front of us.”

“We went through an opened small gate and they started spraying us with pepper spray. Many suffocated and were run over by people, and all those who were on the floor are martyrs,” he said.

Mohammad Shatat, another eyewitness, described a similar situation. After “the Americans” closed the gates, people “started running towards” one of them, Shatat said. “When the Americans saw this, they opened the gate and sprayed us with pepper spray,” he said.

“People fell on each other and everyone who was behind was stepping on the people in the front,” he said, adding that “people were suffocating and dying.”

US security contractors operate inside the GHF’s aid sites, and the Israeli military is usually positioned outside. CNN has approached the Israeli military for comment on the latest incident.

Hundreds of people have been killed while trying to access aid in Gaza since the GHF began operating in the Strip, according to the UN High Commissioner for Human Rights. Nearly 800 people were killed in this way between late May and July 7, it said, 615 of whom were killed near GHF sites.

Palestinian officials and witnesses have said the Israeli military is responsible for most of those deaths. The military has acknowledged firing warning shots towards crowds in some instances, and denied responsibility for other incidents. In late June, the military said it had “reorganized” the approach routes to aid sites to minimize “friction with the population.”

On Saturday, the Palestinian health ministry said 27 people were killed and many more injured when Israeli troops opened fire on people trying to obtain aid from a distribution site run by the GHF near southern Rafah.

The GHF denied the claim, saying “there were no incidents at or in the immediate vicinity of our sites” on Saturday.

The Israeli military also denied that anyone was injured by gunfire from its troops in the vicinity of the site but said it continued to review the reports. It told CNN Sunday it had no further comment.

A scathing US government assessment of the GHF reported on by CNN last week shows that USAID officials raised “critical concerns” about the group’s ability to protect Palestinians and to deliver them food.

The assessment flagged a range of concerns, from an overall plan missing “even basic details” to a proposal to potentially distribute powdered baby formula in an area that lacks clean water to prepare it.

A GHF spokesperson defended the organization’s work in Gaza and described the USAID assessment as normal for a funding application.

In its statement released Wednesday, the Palestinian health ministry said that “the Israeli occupation and the American establishment are deliberately committing massacres in a systematic manner and using various methods against the starving people.”