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At least 27 Palestinians were killed waiting for aid at a Gaza distribution centre when Israeli troops opened fire in the southern city of Rafah on Tuesday morning, the enclave's Health Ministry said.
It was the third day of chaos and bloodshed during aid operations carried out by the Gaza Humanitarian Foundation, a controversial US and Israel-backed group that began work after Israel eased its blockade on Gaza. The foundation's plans, which bypass traditional humanitarian groups, have been condemned by the UN and established charities, who say they do not follow humanitarian principles.
"Israeli artillery and aircraft fired shells and gunfire at displaced people as they waited for aid near a humanitarian aid distribution point," the Wafa news agency reported on Tuesday, adding that at least 90 people were injured.
The Red Cross said it received a "mass casualty influx" of 184 people in Rafah early on Tuesday, most of whom had gunshot wounds and said they had been trying to reach an aid site. It said 27 were people killed.
on Sunday, 31 people were killed in a similar incident near a distribution centre run by the foundation. Three were killed on Monday.
The Israeli military said on social media that it fired shots at people about 500 metres from the distribution site on Tuesday morning after "identifying a number of suspects" who deviated from designated access routes.
"The forces fired evasive shots and, after they did not move away, additional shots were fired near the individual suspects who were advancing towards the forces," the military said.

"Reports of casualties are known. Details of the incident are under investigation," it added. The military said it did "not prevent Gaza residents from reaching the aid distribution complexes".
The US State Department took on a defensive tone after criticism of the aid-distribution mechanism intensified.
State Department spokeswoman Tammy Bruce said journalists had "harangued" her for three months about not enough aid getting into Gaza.
"Seven million meals [have been distributed] and now we're being harangued about [it not being] by the right people. We have to move on from that," Ms Bruce told reporters.
The foundation said it distributed 21 lorryloads of food early on Tuesday and that the operation was "conducted safely and without incident within the site".
Ahmad Bushanaq, 35, told The National he was wounded in the shooting. “I had barely moved 500 metres when the shooting started – from quadcopters and warplanes. I was immediately injured in my leg,” he said. “I was forced to go, even though I knew it wasn’t safe. I have four children, the youngest is just one month old."
Tuesday's deaths came hours after Israel said three of its soldiers had been killed in fighting in northern Gaza, as its forces push ahead with their offensive against Hamas, which has laid waste to much of the enclave.
UN human rights chief Volker Turk said the attacks at the aid sites constituted a war crime. "Deadly attacks on distraught civilians trying to access the paltry amounts of food aid in Gaza are unconscionable," he said. He did not assign blame for the violence.
Mr Turk called for a prompt and impartial investigation into each attack and for those responsible to be held to account. "Attacks directed against civilians constitute a grave breach of international law, and a war crime," he said.
UN Secretary General Antonio Guterres on Monday also called for an independent investigation into the deaths. The UN has criticised the distribution plans of the foundation, which have left the usual co-ordinators of Gaza aid, such as UNRWA, out of the loop.
"Palestinians have been presented with the grimmest of choices: die from starvation or risk being killed while trying to access the meagre food that is being made available through Israel's militarised humanitarian assistance mechanism," Mr Turk said on Tuesday.
Little is known about the foundation. Other aid groups have said its operations endanger civilians by delivering food through narrow, militarised corridors. Israel has described the foundation's methods as a way of circumventing Hamas, which Israel accuses of stealing aid.
Israel has faced mounting international criticism over the humanitarian crisis in Gaza, where the UN has warned the entire population faces famine. Israel imposed an aid blockade on the besieged enclave on March 2 and has only relaxed it in recent days.
Nearly 20 months into the war, negotiations over a ceasefire between Israel and Hamas remain deadlocked. A brief truce collapsed in March and Israel has since intensified operations to “destroy” the group.