The Israeli military says an investigation "outside the chain of command" has been launched into the killing of Palestinian medics and emergency responders in southern Gaza, but denies the group had been "executed."
On Sunday, 15 bodies were recovered from what the United Nations has described as a "mass grave", a week after they were fired upon by Israeli forces.
The United Nations (UN) and humanitarian organisations have levelled serious allegations at the Israel Defense Forces (IDF) over the incident near Tel al-Sultan, including that vehicles clearly marked as ambulances and fire trucks were targeted by troops.
The IDF had been roundly criticised for restricting access to crews trying to recover the bodies for days, and there are questions as to why the remains were buried under sand alongside the wreckage of bombed out vehicles.
In the days since the discovery, there have been demands for accountability from Israeli forces for the killings, including from the UK and German governments.
On Thursday, the IDF's spokesman said a probe had begun.
"I don't want to jump ahead of the investigation, but [it's] definitely not an execution," Lieutenant Colonel Nadav Shoshani told a press briefing.
"This was an operational event in a live combat zone.
"We'll look into this event, in the most serious way we can."
He said the military's general staff mechanism would conduct the investigation.
For days, the IDF had refused to answer questions about the mass grave that the eight paramedics from the Palestinian Red Crescent Society, six Gaza civil defence service emergency responders and one UN worker had been found.
An IDF official later confirmed troops had buried the men under sand and cloth sheets.
A ninth medic is still missing.
Israel had insisted the ambulances and fire trucks had approached troops in a suspicious manner.
"Very, very weird for a car like that to have no lights on, no emergency lights," Lieutenant Colonel Shoshani said.
The IDF had claimed a group of other vehicles had been targeted prior to the emergency convoy arriving, and that nine Hamas and Palestinian Islamic Jihad (PIJ) terrorists had been killed.
It has only named one of the fighters killed, and Lieutenant Colonel Shoshani refused to detail what evidence the IDF had about other fighters being killed.
Despite insisting he did not want to pre-empt the inquiry, he suggested terrorists could have been posing as medics — again, without providing any detail.
"There were not just eight people there or nine people there - there were more people there, and we're trying to understand," he said.
"In many cases, we've seen throughout this war, that Hamas members or terrorists in Gaza have what we call a day job.
"Our initial investigation found that there were terrorists in these cars, using those Red Crescent cars."
Lieutenant Colonel Shoshani also criticised The Guardian for reporting comments from a forensic consultant in Gaza, who said there was evidence of execution-style killings.
He did not provide any details to back up his rejection of the comments.
Killings prompt outrage
In the wake of the bodies being discovered, the International Federation of Palestinian Red Cross and Red Crescent Societies (IFRC) expressed outrage at the killing of medics.
The organisation did not comment on the Israeli investigation, but reiterated its condemnation of the attack.
"The eight paramedics were killed while wearing their uniforms and operating in clearly marked ambulances, carrying out life-saving duties," it said in a statement.
"The Red Crescent emblem, recognised under international humanitarian law, is meant to afford them protection.
"This must stop. As a neutral organisation, we reiterate our call for the need to protect our staff and volunteers, humanitarian workers, paramedics, and civilians."
British Foreign Secretary David Lammy was among those calling for action.
"Gaza remains the deadliest place for humanitarians — with over 400 killed," he told the UK parliament on Tuesday.
"Recent aid worker deaths are a stark reminder.
"Those responsible must be held accountable."