Ramallah, March 1 (RHC)-- Palestinian leaders and countries around the world have condemned Israel’s targeting of unarmed Palestinians collecting aid in Gaza, in an attack that has killed more than 100 people.

The office of Palestinian Authority President Mahmoud Abbas said an “ugly massacre conducted by the Israeli occupation army” had taken place, following reports on Thursday that Israeli forces opened fire on people receiving aid southwest of Gaza City.

The Gaza Ministry of Health said at least 104 people were killed and more than 750 wounded, and called on the international community to “urgently intervene” to forge a ceasefire as “the only way to protect civilians”.

“The killing of this large number of innocent civilian victims who risked their livelihood is an integral part of the genocidal war committed by the occupation government against our people,” Abbas’s office was quoted by the Wafa news agency as saying.  “Israeli occupation authorities bear full responsibility and will be held accountable before international courts.”

Palestinian group Hamas called the attack “a heinous massacre added to the long series of massacres committed by the criminal Zionist entity against our Palestinian people”.

In a statement, the group, which is fighting Israel in Gaza, said the deadly attack on aid-seekers was “unprecedented in the history of war crimes” and was part of Israel’s “war of starvation” against Palestinians in the enclave.

It called on the United Nations Security Council and Arab states to take decisions obligating Israel to stop its mass killings, ethnic cleansing, genocide and violations of international law in Gaza.

Hamas also said it holds Israel and the United States administration under President Joe Biden responsible for the escalation of the war.

After news of the attack, the Israeli army claimed that civilians in Gaza had attacked the aid trucks and dozens of people had been trampled – although this was disputed by witness accounts.  “At some point, the trucks were overwhelmed and the people driving the trucks, which were Gazan civilian drivers, ploughed into the crowds of people, ultimately killing, my understanding is, tens of people,” Israeli government spokesperson Avi Hyman told reporters.

Palestinian novelist Yusri al-Ghoul, who witnessed to the incident, spoke to Al Jazeera from Gaza City’s Shati Camp.  “They [Israel] are always saying their propaganda … I heard them when they are insulting us and shouting at the Palestinians, even the children … [saying] we will kill you every day,” he said.

“[If it was because of overcrowding], why were the knees and elbows being shot? … Why did the Israeli tanks target the Palestinian civilians?”  The White House said it was looking into reports of Israeli fire on Palestinians, describing it as a “serious incident.”

“We mourn the loss of innocent life and recognise the dire humanitarian situation in Gaza, where innocent Palestinians are just trying to feed their families,” a White House National Security Council spokesperson said in a statement on Thursday.

U.S. President Joe Biden later said that Washington was checking “two competing versions of what happened,” before adding that the killings would make negotiations over a ceasefire in Gaza more difficult.

The United Nations’ aid chief Martin Griffiths said he was appalled at the “reported killing and injury of hundreds of people.”  “Even after close to five months of brutal hostilities, Gaza still has the ability to shock us,” Griffiths said. “Life is draining out of Gaza at terrifying speed.”

Egypt, which neighbours Israel and the southern Gaza Strip, meanwhile condemned the attack.  “We condemn the inhumane Israeli targeting of … unarmed Palestinian civilians in the Nabulsi roundabout in the northern Gaza,” Egypt’s foreign ministry said in a statement. “We consider targeting peaceful citizens rushing to pick up their share of aid a shameful crime and a flagrant violation of international law.”

Jordan’s foreign ministry also released a statement, saying, “We condemn the Israeli occupation forces’ brutal targeting of the gathering of Palestinians who were waiting for aid on the Nabulsi roundabout near Al-Rashid Street in Gaza.”

Saudi Arabia also joined in the condemnation. A foreign ministry statement said Riyadh rejected “violations of international humanitarian law from any side and under any circumstance”, and called for the international community to compel Israel to open secure humanitarian corridors into Gaza.

For her part, the Belgian deputy prime minister, Petra De Sutter, said she was “horrified by the news of today’s massacre.”  “Murdering people queueing for essential humanitarian aid?” De Sutter wrote in a social media post.  “This is a flagrant violation of international humanitarian law and fully goes against the [International Court of Justice’s] provisional measures.”

Mustafa Barghouti, the secretary-general of the Palestinian National Initiative, called the attack another “horrible crime” committed by Israel.  “These were civilians who are starving because Israel has been depriving them from food for months and does not allow any supplies to them for more than a month now,” he told Al Jazeera from Moscow.

“And then they try to justify it by saying that Palestinians are responsible for being killed by the same Israeli soldiers? It’s unbelievable.”

Barghouti also decried “the silence” of Western countries and blamed their governments for being “complicit with these crimes and allow them to happen.”  “This should stop immediately,” he said. “It cannot stop without an immediate, permanent, complete and total ceasefire.”