The Israeli military opened fire near hundreds of Palestinians waiting for aid trucks in central Gaza on Tuesday, killing at least 25 people, according to hospitals in the Strip.
The Awda hospital in the Nuseirat refugee camp, which received some of the victims, said 146 others were wounded, among them 62 in critical condition, who were transferred to another hospital in central Gaza.
An eyewitness said drones were flying over the area before there was gunfire from tanks and drones. He described the scene as "chaotic and bloody" as people were trying to escape.
The Israeli army has not commented on the incident so far.
Over 410 Palestinians have been killed since the Israel- and US-backed aid delivery network, the Gaza Humanitarian Foundation (GHF), started operating on 27 May, the UN Human Rights office said on Tuesday.
"The weaponisation of food for civilians ... constitutes a war crime," UN Human Rights spokesperson Thameen Al-Kheetan told reporters at a press briefing in Geneva.
"Desperate, hungry people in Gaza continue to face the inhumane choice of either starving to death or risk being killed while trying to get food."
The head of the UN agency for Palestinian refugees (UNRWA), Philippe Lazzarini, similarly slammed Israel's aid distribution mechanism in Gaza, calling it an "abomination that humiliates and degrades desperate people."
"It is a death trap costing more lives than it saves," he told a briefing in Berlin.
Israel has said the mechanism is necessary to prevent Hamas from war profiteering and strengthening its group by stealing aid meant for civilians in the Strip.
Israeli forces have been repeatedly accused of opening fire at crowds in desperate need of food. The military said it fired warning shots at people who it considered to have approached its forces in a "suspicious manner".
The UN called for an urgent and impartial investigation into each of the killings, and urged Israel to allow the entry of food and humanitarian aid into the strip, "in accordance with international law an humanitarian principles."
