The Palestinian ambassador to the United Nations has condemned Israel’s attack on Nasser Hospital as “a premeditated strike on medics and journalists”.

The envoy’s comments are the latest condemnation of the 25 August attack that killed 22 people, including five journalists. They come as an investigation by Sky News raises new questions about the incident.

The IDF said the strike targeted an “observation camera” used by Hamas to monitor troop movements from the hospital, adding that six of those killed were “terrorists”.

But the camera that the IDF struck was broadcasting a live stream for the news agency Reuters, and the IDF has said that the journalist operating this camera was “not a target”.

The Israeli military has not indicated that any other camera was on the balcony, and the hospital’s director says the only person on the balcony was the Reuters journalist.

Sky News did find evidence that one of the six people named by the IDF was a militant, but we also found evidence that he was killed in a separate incident, not at Nasser Hospital.

Most of those killed died when the IDF launched a second strike on the same stairwell, around eight minutes after the first, as rescue efforts were under way. Video seen by Sky News shows two missiles hitting the hospital in the second strike.

Speaking at the UN Security Council on 27 August, Palestinian UN envoy Riyad Mansour said: “The second strike on Nasser hospital was a premeditated strike on medics and journalists who arrived at the scene after the first strike.

“While the world demands a permanent ceasefire, Israel continues its crimes. Where else is the killing of so many civilians and journalists tolerated?”

Here’s what we know

At around 10am on Monday 25 August, journalist Hossam Al Masri, 49, was operating a Reuters live stream from the top floor of Nasser Hospital, in Khan Younis.

Footage from the livestream shows Hossam filming the busy market outside the hospital, before raising the camera and zooming in on a cloud of black smoke rising in the distance.

At that moment, the feed froze. Reports emerged, starting at 10.09am, of an explosion at the hospital.

Soon, footage showed smoke rising over the building, and a chunk of concrete missing from the exterior stairwell where Hossam had been filming.

Journalists and rescue workers quickly rushed to the site in search of survivors. They found two bodies, including Hossam’s.

At 10.17am, as rescue efforts continued, a second Israeli strike hit the stairwell.

Three loud bangs could be heard at the moment of impact.

Footage from the ground shows at least two projectiles impacting in quick succession, with just milliseconds between them.

An Israeli military official told the Press Association that the strikes were carried out by tanks.

Amael Kotlarski, weapons team manager at defence intelligence company Janes, told Sky News that the shape of the projectile and resulting damage is consistent with powered, precision-guided munitions such as Lahat laser-guided missiles.

These can be fired from tanks or helicopters. “The IDF is known to have stocks of the air-launched version, it is unclear if the gun-launched version were procured,” he says.

“If these Lahats were fired from the ground, then at least two tanks would have been involved, as the interval between the two impacts is far too short.”

Sky News analysis of the footage suggests that the projectiles were fired from the northeast.

Satellite imagery taken approximately five hours after the attack shows six tanks stationed at a fortified base around 2.4km northeast of the hospital, though Sky News is unable to say whether they were involved in the attack.

Why did Israel attack the hospital?

Footage filmed from the ground shows smoke billowing out of the hospital as people flee.

As the smoke cleared, rescue workers returned to the scene. What they saw is too graphic to publish – at least seven bodies scattered throughout the stairwell.

Health officials have since put the total number killed at 22, including a rescue worker, a doctor, three hospital staff and five journalists.

On Tuesday, the IDF said that Israeli troops had targeted a camera “that was positioned by Hamas in the area of the Nasser Hospital [and] that was being used to observe the activity of IDF troops”.

However, Sky News has confirmed that the initial strike hit Reuters cameraman Hossam Al Masri, who was operating a livestream for the international news agency at the time of the attack.

Footage from the aftermath of the first strike shows that it hit the top balcony on the hospital’s exterior stairwell.

Sky News was able to confirm that the livestream recorded by Hossam was taken from this balcony, based on the buildings visible and a wooden beam obstructing the camera’s field of view.

This conclusion is supported by eyewitness testimony, as well as the fact that the feed cut unexpectedly, but without showing any attack on the hospital, and that Al Masri’s death was the first to be reported, at 10.18am.

The IDF said that Al Masri was “not a target” of the strike. It did not specify whether his camera was the same one it believes was positioned and used by Hamas.

The IDF has not suggested that there was any other camera on the balcony.

Speaking to Sky News on Wednesday, the director of Nasser Hospital, Dr Atef Al Hout, said that Hossam “was the only one on that floor in that moment”.

On Monday, Israeli outlet Channel 12 published an undated aerial photograph of a camera, shared by an anonymous military source, which Sky News matched to the same balcony.

The unnamed source pointed to a white towel placed over the camera as evidence that it was being concealed.

Medics and journalists at Nasser Hospital told Sky News that towels, such as the one visible in the photo, are used to prevent cameras from overheating, and this specific location is frequently used by media workers.

Reuters had been delivering daily livestreams from the position for several weeks before the attack.

And the video below, uploaded on 10 June, shows multiple journalists using the space to record video or get phone signal.

Among those visible in the video are journalists Mariam Abu Daqqa and Mohammed Salama, who were killed in Monday’s attack.

“This is among the deadliest Israeli attacks on journalists working for international media since the Gaza war began,” the Foreign Press Association said in a statement on Monday, adding the strikes came “with no warning”.

Brian Finucane, who spent a decade advising the US State Department on conflict law, says hospitals are protected from attack under international law.

“Hospitals may lose this protection if they are used to commit acts harmful to the enemy outside of their normal humanitarian function – but only if prior advance warning is given to allow for the termination of such harmful acts,” he says.

Former United States Ambassador-at-Large for War Crimes Stephen Rapp told Sky News that “an independent investigation is clearly warranted”.

Sky News asked the IDF whether any advance warning was provided to the hospital, but did not receive a response to this question.

Hamas denied using the camera targeted by the IDF, describing this allegation as “a baseless allegation devoid of any evidence, intended solely to evade legal and moral responsibility for a fully-fledged massacre”.

Who was killed?

In its statement on Tuesday, the IDF said that six of those killed were “terrorists” and part of Hamas and Islamic Jihad.

Sky News examined social media pages and obituaries for each of these six people.

We found evidence that one of those named, Omar Abu Teim, had been a combatant.

But while obituaries by family and friends of the other five individuals all reference the attack on Nasser Hospital, those for Abu Teim do not.

A neighbour and childhood friend of Abu Teim’s told us he had died while taking part in an attack on a new IDF position east of Khan Younis – not at Nasser Hospital.

A Hamas-branded obituary identifies Abu Teim as a “hero of the storming of the new site” alongside four others. Sky News has not been able to verify whether Abu Teim was formally part of Hamas or a different militant group.

Ramy Abdu of Euro-Med Human Rights Monitor told Sky News his team saw the Abu Teim family searching for their son’s body the day before the hospital strike, adding that the body has still not been recovered.

Abu Teim’s neighbour also said his body has not been recovered, and Gaza’s health ministry told Sky News it had not received his body in any of its hospitals.

The IDF told Sky News it was examining whether Abu Teim was killed in a separate incident.

Hamas has denied that any of its fighters were killed in the attack on Nasser Hospital.

No explanation given for second strike

The Israeli military has not explained the reason for the second strike on the stairwell, which occurred while rescue efforts were under way and caused the greatest number of deaths.

Such ‘double-tap’ strikes carry significant risks for emergency personnel and journalists, who often gather at the scene of attacks.

Sky News asked the IDF who was being targeted in the second strike, but the military did not respond to this question.

Emily Tripp, executive director of conflict monitoring group Airwars, says that double-tap strikes are something they have seen “consistently” throughout the war, although the intensity of the bombardment has made it difficult to confirm timings.

Her team has documented 24 separate double-tap strikes across Gaza since the war began.

At least 190 journalists have been killed in Gaza since the war began, according to the Committee to Protect Journalists.

The Aid Worker Security Database has also documented 536 killings of aid and rescue workers as of 2 August. This number does not include the 139 reported deaths among workers from Gaza’s Civil Defence rescue agency.

Reuters did not respond to a request for comment.

Additional reporting by Freya Gibson, OSINT producer, and production by Michelle Inez Simon and Celine Al Khaldi.

The Data and Forensics team is a multi-skilled unit dedicated to providing transparent journalism from Sky News. We gather, analyse and visualise data to tell data-driven stories. We combine traditional reporting skills with advanced analysis of satellite images, social media and other open source information. Through multimedia storytelling we aim to better explain the world while also showing how our journalism is done.