A US- and Israeli-backed private aid organisation that distributes food and supplies inside Gaza has confirmed 20 Palestinians were killed at one of its sites in the south of the strip on Wednesday morning.
The GHF said 19 people were trampled and another was stabbed, as the crowd surged at the site in Khan Younis.
It blamed what it described as "agitators" in the crowd, saying it believed they were linked to Hamas.
"We have credible reason to believe that elements within the crowd — armed and affiliated with Hamas — deliberately fomented the unrest," GHF said in a statement.
"For the first time since operations began, GHF personnel identified multiple firearms in the crowd, one of which was confiscated. An American worker was also threatened with a firearm by a member of the crowd during the incident."
GHF said the incident followed a "troubling pattern" of false information about aid site openings being circulated online.
"False messages about aid site openings, including at SDS4 (Wadi Gaza) and the long-closed SDS1 (Tal Sultan), have circulated widely on Telegram and other platforms, fuelling confusion, driving crowds to closed sites, and inciting disorder," the statement said.
The previous day, GHF said large crowds had gathered at the Khan Younis site, forcing the organisation to close its doors and stop distributing aid there.
It said 18 truckloads of aid were distributed at the site, one of only two seemingly in operation this week.
GHF-run sites hazardous for desperate Palestinians
The international humanitarian community has been scathing in its criticism of the GHF-run sites, saying they were death traps for desperate Palestinians trying to access food.
There have been multiple shootings outside the distribution facilities in recent weeks, which local health authorities said have killed hundreds of Palestinians.
GHF has repeatedly rejected those claims, but added that it does not have responsibility for incidents happening in the areas outside of its distribution sites.
The Israel Defense Forces has admitted firing warning shots at some of the sites, but has denied being involved in mass shootings.
GHF has been accused of running too few aid sites across Gaza, resulting in Palestinians having to trek for hours on foot to access the distribution facilities that have been handing out supplies.
It has rejected comments from the UN that more than 800 Palestinians have been killed near its sites in recent weeks, arguing that it is based on information from the Hamas-run Gaza health authorities.
Israeli authorities repeatedly dismiss reports of deaths and injuries coming from local medics, saying information coming out of Gaza is Hamas propaganda.
But Israel does not allow any media to enter the strip to verify the data itself.