More than 300 bodies have been uncovered so far from the hospital after Israeli forces withdrew on April 7. The UN Human Rights Council on Tuesday said more bodies were found at Gaza City’s al-Shifa Hospital, the enclave’s largest health facility, which the rights body said was “an empty shell” after a two-week Israeli siege ended there on April 1.

The mass graves at Gaza’s two largest medical facilities are among the several discovered since Israel launched its war on the besieged coastal enclave on October 7, killing more than 34,000 Palestinians. Israel’s offensive came after Hamas fighters carried out attacks inside Israel, killing 1,139 people.

Here is what we know about the mass graves uncovered so far:

What has been found so far?

Gaza civil defence crews said more than 300 bodies have been recovered from the mass grave at the Nasser Medical Complex so far.

According to Al Jazeera’s correspondent Hani Mahmoud, those being retrieved from the grave included women, children, patients and medical staff.

He said medical staff and evacuees who had managed to leave the hospital before the Israeli army’s withdrawal had described scenes of “horror, mass killings and arrests to the point the entire hospital turned from a place of healing into a massive graveyard”.

The civil defence group on Monday said it uncovered many of the bodies from what appear to be temporary graves inside the Nasser complex as Israel’s siege prevented access to cemeteries, The Associated Press news agency reported.

Ravina Shamdasani, a spokeswoman with the UN’s human rights office, said some of the bodies found at the Khan Younis hospital were “found with their hands tied and stripped of their clothes”.

What is a mass grave?

There is no international definition of a mass grave. However, forensic experts define a mass grave as a “burial site containing the remains, often commingled, of numerous persons”.

Mass graves are not necessarily burial sites or final resting places but “are places of atrocity or mass death”, a UN report published in October 2020 said.

“What distinguishes mass graves from other mass burial sites are violations of ‘last rights’ and of last rites, including suppression or even annihilation of individual, cultural or religious identity in death,” the report said.

What has been the reaction from Israelis and Palestinians?

Gaza’s Government Media Office blamed Israel for the mass graves, describing their discovery and the overall situation at Nasser Medical Complex as a “heinous crime”.

“Storming it twice, and destroying some of its parts, demonstrates the extent of the barbarism of this occupation and the immorality of its army, which destroys all aspects of life and means of survival inside the Gaza Strip,” it said in a statement.

“We call on the Prosecutor of the International Criminal Court to investigate this massacre committed by the occupation army in the Nasser Complex and also the al-Shifa Complex, in all its details, whether against the headquarters of the two complexes or against the citizens, the displaced, and the medical and Media teams inside it.”

The Israeli army said in a statement on Tuesday that the claim that it buried Palestinian bodies was “baseless and unfounded”.

It said that during its operation in the area of Nasser Hospital, bodies buried by Palestinians “were examined” to try “to locate hostages and missing persons”. Dozens of Israelis remain in  captivity, held by Hamas and other Palestinian fighters in Gaza.

“The examination was conducted in a careful manner and exclusively in places where intelligence indicated the possible presence of hostages,” it said, adding that the examined bodies, which did not belong to Israeli captives, “were returned to their place”.

What has been the global reaction?

The UN called for “a clear, transparent and credible investigation” of mass graves uncovered at the two hospitals.

Shamdasani called for an independent and transparent investigation into the deaths and bodies found, saying “given the prevailing climate of impunity, this should include international investigators.”

Credible investigators must have access to the sites, UN spokesman Stephane Dujarric said.

The European Union on Wednesday backed a UN call for an independent probe.

“This is something that forces us to call for an independent investigation of all the suspicions and all the circumstances because indeed it creates the impression that there might have been violations of international human rights committed,” EU spokesman Peter Stano said.

“That’s why it’s important to have independent investigation and to ensure accountability.”

In Washington, US Department of State spokesman Vedant Patel described the discovery of mass graves as “incredibly troubling”, adding that US officials asked the Israeli government for information.

The Saudi Arabian Ministry of Foreign Affairs in a statement condemned “the continued and unchecked heinous war crimes committed by the Israeli occupation forces, the latest of which is the mass graves discovered in the Nasser Medical Complex in the city of Khan Younis”.

Are there any legal ramifications?

According to UN human rights chief Volker Turk, “Hospitals are entitled to very special protection under international humanitarian law.”

“Let’s be clear, the intentional killing of civilians, detainees and others who are hors de combat [disabled or injured] is a war crime,” he said on Tuesday.

Israeli operations in Gaza have come under heavy scrutiny from international bodies and human rights groups. A UN investigator last month said in a report that there were reasonable grounds to believe Israel has committed genocide in its war on Gaza.

In January, the International Court of Justice ordered Israel to refrain from any acts that could fall under the Genocide Convention and ensure its troops commit no genocidal acts against Palestinians in Gaza.

Israel described the genocide allegation as baseless.