The Nasser hospital in southern Gaza has said 24 people have been killed near an aid distribution site.
Palestinians who were present at the site said Israeli troops opened fire as people were trying to access food on Saturday.
The Israel Defense Forces (IDF) said there were “no known injured individuals” from IDF fire near the site.
Separately, an Israeli military official said warning shots were fired to disperse people who the IDF believed were a threat.
The claims by both sides have not been independently verified. Israel does not allow international news organisations, including the BBC, into Gaza.
Footage seen by the BBC later on Saturday showed what appeared to be a number of body bags at Nasser hospital’s courtyard surrounded by nurses and people in blood-stained clothes.
In another video, a man said people were waiting to get aid when they came under targeted fire for five minutes. A paramedic accused Israeli troops of killing in cold blood.
The videos have not been verified by the BBC.
Reuters said it had spoken to witnesses who described people being shot in the head and torso. The news agency also reported seeing bodies wrapped in white shrouds at Nasser hospital.
There have been almost daily reports of people being killed by Israeli fire while seeking food in Gaza.
Israel imposed a total blockade of aid deliveries to the Gaza Strip in March, and later resumed its military offensive against Hamas, collapsing a two-month ceasefire. It said it wanted to put pressure on the Palestinian armed group to release Israeli hostages.
Although the blockade was partially eased in late May, amid warnings of a looming famine from global experts, there are still severe shortages of food, as well as medicine and fuel.
The UN agency for Palestinian refugees, Unrwa, says there are thousands of malnourished children across the territory, with more cases detected every day.
In addition to allowing in some UN aid lorries, Israel and the US set up a new aid distribution system run by the Gaza Humanitarian Foundation (GHF), saying they wanted to prevent Hamas from stealing aid.
On Friday, the UN human rights office said that it had so far recorded 798 aid-related killings, including 615 in the vicinity of the GHF’s sites, which are operated by US private security contractors and located inside military zones in southern and central Gaza.
The other 183 killings were recorded near UN and other aid convoys.
The Israeli military said 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 accused the UN of using “false and misleading” statistics from Gaza’s Hamas-run health ministry.
Earlier this month, a former security contractor for the GHF told the BBC he witnessed colleagues opening fire several times on hungry Palestinians who had posed no threat. The GHF said the allegations were categorically false.
Israel launched a military campaign in Gaza in response to Hamas’ cross-border attack on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.
At least 57,823 people have been killed in Gaza since then, according to the Hamas-run health ministry.