"The incident from March 23, 2025, in which IDF (military) forces opened fire targeting terrorists advancing in ambulances, has been transferred to the General Staff's fact-finding and assessment mechanism for investigation," military spokesman Lieutenant Colonel Nadav Shoshani said in a statement.

The Palestinian Red Crescent said on Sunday it had recovered the bodies of 15 rescuers after Israeli forces targeted the ambulances in the southern Gaza Strip last month.

One Red Crescent emergency responder was still missing, according to the group.

Bodies of eight medics from the Red Crescent, six members of Gaza's civil defence agency and one employee of a UN agency were retrieved, the Red Crescent said in a statement.

The UN humanitarian office (OCHA) said Tuesday that a team of first responders was killed by Israeli forces on March 23, and that other emergency and aid teams were hit one after another over several hours while searching for their missing colleagues.

"The (Israeli military) places utmost importance on maintaining communication with international organisations operating in Gaza and engages with them regularly," Shoshani said in a statement on Thursday.

In a briefing with journalists, Shoshani said the incident was being investigated.

"We want to have all the facts in a way that's accurate and we can also hold accountable people if we need to, or put the facts straight as they are, and learn from this incident or whatever it may be," he said.

"There is an external... figure that is investigating this event, understanding everything that happened", he added.

- Mass grave -

UN aid official Jonathan Whittall said Wednesday that a mass grave in Rafah where the bodies of the 15 medics were found illustrated the "war without limits" that Israel is leading in Gaza.

An Israeli military official said the army "contacted the organisations multiple times to coordinate the evacuation of the bodies, in accordance with the operational constraints".

"Understanding that the process might take time, the bodies were covered with sand and cloth sheets so that they wouldn't get damaged," the official said.

The military has not formally responded to claims that the bodies were dumped in a mass grave.

But in an earlier statement the military had said that an initial assessment of the incident determined that its troops had "eliminated a Hamas military operative, Mohammad Amin Ibrahim Shubaki, along with eight other terrorists from Hamas and Islamic Jihad".

Speaking after a mission to Gaza uncovered the mass grave, Whittall, the head of OCHA in the Palestinian territories, said "it was shocking" to see medical workers "still in their uniforms, still wearing gloves, killed while trying to save lives".

UN chief Antonio Guterres voiced alarm over the killings.

"The secretary-general is shocked by the attacks of the Israeli army on a medical and emergency convoy on March 23 resulting in the killings of 15 medical personnel and humanitarian workers in Gaza," spokesman Stephane Dujarric told a briefing Wednesday.