The Israeli military has acknowledged flaws in its initial accounts of its troops’ involvement in the killing last month of 15 people in southern Gaza who the United Nations said were all paramedics and rescue workers.

The admission came on Saturday, the day after a video obtained by The New York Times appeared to contradict a key part of the military’s earlier version of events. While the military had said it fired on the vehicles after they “advanced suspiciously,” the video showed clearly marked ambulances and a fire truck.

The episode has drawn international scrutiny and condemnation. After the blatant inconsistencies in the Israeli account were revealed, the military seemed to move more quickly than usual to address the issue. Internal military inquiries into questionable deadly episodes can drag on for months, even years.

Here’s what we know so far:

The Israeli military’s version(s)

In its initial statements after the bodies were discovered, the military insisted its troops had opened fire as a convoy approached them in the dark “without headlights or emergency signals.”

But the video — discovered on the cellphone of a paramedic who was found in a mass grave — shows that the ambulances and fire truck had emergency lights on as Israeli forces unleashed their barrage.

The military now says the initial account from forces on the ground was “mistaken.”

Military officials had previously asserted that nine of those killed were operatives of Hamas or Islamic Jihad. They had named only one of the nine and provided no evidence for their claim.

On Saturday, a military official who briefed reporters on the initial findings of an internal inquiry said at least six of the 15 were Hamas operatives but still did not provide evidence. The official spoke on the condition of anonymity under army rules.

Before the encounter with the emergency vehicles, the official said, reserve forces from an infantry brigade had been lying in ambush along a road to the north of the Gazan city of Rafah before dawn on March 23. At 4 a.m., they killed what the official described as two Hamas security personnel and detained a third.

Two hours later, as dawn was breaking, the emergency convoy approached the same spot. When the rescue workers began to leave their vehicles, the official said, the Israeli forces believed that they were Hamas operatives heading for them and opened fire from afar.

Amos Harel, a military affairs analyst for the left-leaning newspaper Haaretz, said in an interview that the soldiers had “good reason to be anxious” and that it would be wrong to assume immediately that the case was one of “murder in cold blood,” citing Hamas fighters’ frequent use of civilian infrastructure as cover.

But the episode raises questions, Mr. Harel said, about the soldiers’ conduct and the version of events they reported from the ground.

The military official denied reports that some of the bodies were found bound and shot at close range. He said that the troops had buried the bodies to shield them from wild animals and used heavy equipment to move the disabled vehicles off the road, mangling them.

What the aid groups say

Palestine Red Crescent Society representatives said last week that ambulances had set out around 3:30 a.m. on March 23 to evacuate Palestinian civilians wounded by Israeli shelling.

The Red Crescent said that an ambulance and its crew had been hit by Israeli forces and that several more ambulances and a fire truck headed to the scene over the next few hours to rescue them. A U.N. vehicle was also sent, the United Nations said.

Seventeen people were dispatched in total, of whom 10 were Red Crescent workers, six were emergency responders from Gaza’s civil defense service and one was a U.N. worker.

It took days to negotiate access to retrieve the 15 bodies. The Red Crescent said that one medic was still missing and that one, Munther Abed, had been detained by Israeli forces and later released.

The Red Crescent said Israel’s “targeting” of its medics should be “considered a war crime” and demanded an investigation. It added that the latest killings brought to 27 the number of its members killed during the war, which started on Oct. 7, 2023, with a deadly Hamas-led attack.

On Friday, the president of the Palestine Red Crescent Society, Dr. Younis Al-Khatib, told reporters that, based on autopsies and forensic evidence, the emergency workers had been “targeted from a very close range.”

Reaction in Israel so far

The case has received broader coverage in Israel since the exposure of the video. Politicians have mostly remained silent, perhaps waiting for the military to complete its inquiry.

Mr. Harel, the military affairs analyst, said the inquiry was a first test for the recently installed military chief of staff, Lt. Gen. Eyal Zamir, regarding the military’s international standing.

And the larger question of accountability remains. Yesh Din, an Israeli human rights organization, found last year that of 573 cases of suspected war crimes in Gaza examined over the past decade by the army, only one led to prosecution.

Gabby Sobelman contributed reporting from Rehovot, Israel.