Israel struck Nasser Hospital at least four times during its deadly attack in southern Gaza on Monday, an analysis of new video footage by BBC Verify has found.

The attack, which has attracted international condemnation and widespread anger, reportedly killed at least 20 people, including five journalists.

Initial reports from Gaza said that Israel had struck the hospital twice, with the first blast followed nine minutes later by another which hit first responders and journalists who arrived at the scene.

But new analysis suggests the hospital was struck four times in total. BBC Verify and expert analysis found that two staircases were hit almost simultaneously in the first wave, and while what was thought to be a single later attack was in fact two separate strikes hitting the same place within a fraction of a second.

Israel does not allow international journalists to enter Gaza independently. BBC Verify identified the additional strikes by analysing dozens of videos provided by a freelancer on the ground and material filmed by eyewitnesses that circulated online.

In the first incident, an Israeli strike hit the exterior staircase on the hospital’s eastern side at 10:08 local time (07:08 GMT), killing journalist Hussam Al-Masri who was operating a live TV feed for Reuters.

BBC Verify has now identified another previously unreported blast at a northern wing staircase at practically the same time, which was overshadowed by the “double-tap” strike on the eastern staircase.

New footage shows smoke rising and damage at both staircases, while emergency workers said the hospital’s operating department was hit.

Other videos show an injured person being carried down the northern staircase and the hospital’s nursing director holding shredded and bloodied clothing which he said was being worn by a nurse while she was working in the operating department when it was hit.

N R Jenzen-Jones – the director of Armament Research Services, an arms and munitions intelligence company – said the footage “appears to show interior damage consistent with a relatively small munition, including an entry hole that suggests a munition with a relatively flat trajectory”.

Roughly nine minutes later, while dozens of first responders and journalists gathered on the eastern staircase, Israeli forces struck the facility again.

While the blast was documented by media at the time, frame-by-frame analysis of newly emerged footage clearly shows that two separate projectiles fired by Israeli forces hit the hospital milliseconds apart at an exposed stairwell where journalists and emergency workers had gathered.

Experts disagreed on the type of munition used in the third and fourth strikes.

Some munitions analysts with whom BBC Verify shared footage with identified the projectiles as Lahat missiles, a guided munition which can be fired from tanks, drones and helicopters. Several outlets in Israel have suggested that the munitions used against the hospital were fired by Israeli tanks stationed nearby.

The experts who spoke to BBC Verify said the blasts could not have been caused by a single tank, due to the quick succession in which the munitions hit the hospital.

“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,” Amael Kotlarski, an analyst with the Janes defence intelligence company, said. “No tank loader could have reloaded that fast.”

Meanwhile, Mr Jenzen-Jones said that the “impact of two projectiles at nearly the exact same moment suggests two tanks may have fired on the target simultaneously”.

Although he said it wasn’t possible to definitively identify the munitions used, the apparent physical characteristics and pattern of flight “suggest a ‘multi-purpose’ tank gun projectile, such as the Israeli M339 model”.

Satellite images reviewed by BBC Verify show IDF forces 2.5km north-east of Nasser Hospital and within firing range on the day of the attack. Other armoured vehicles can also be seen nearby.

The Israel Defense Forces (IDF) said it had no additional comment on the newly identified blasts when approached by BBC Verify.

Israel’s narrative of the attack has evolved since Monday’s attack. It initially said it had carried out a strike in the area of the hospital, saying that it “regrets any harm to uninvolved individuals ” and that an initial inquiry would be opened as soon as possible, but provided no justification for the attack.

In the hours that followed Prime Minister Benjamin Netanyahu said Israel was responsible and that it “deeply regrets the tragic mishap”.

On Tuesday, the IDF said an initial inquiry found that troops had identified a camera positioned by Hamas in the area of the hospital “used to observe the activity of IDF troops”, without providing evidence.

The IDF has not yet acknowledged carrying out more than one strike on the hospital, amid allegations from some international legal experts that it may have violated international law.

Intentionally carrying out attacks on civilians which are “excessive in relation to the concrete and direct military advantage anticipated” is prohibited under the Fourth Geneva Convention.

“A reasonable attacker must expect scores of civilian casualties since a hospital is full of protected persons,” Professor Janina Dill of Oxford University said.

Prof Dill added that the “mere presence of equipment that belongs to an adversary” does not mean a hospital or medical facility loses its protected status under the laws of war.

At least 247 journalists have been killed in Gaza since 7 October 2023, according to the UN, making it the deadliest conflict for reporters ever documented.

Israel’s military launched a campaign in Gaza in response to the Hamas-led attack on southern Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.

Almost 62,900 people have been killed in Gaza in the same period, according to the Hamas-run health ministry.

Dr Ed Pyne snips a leaf from the Druids Oak, an 800-year-old tree that has watched over this woodland in Buckinghamshire for centuries, enduring droughts, storms, heatwaves and more.

“We know that this tree is a survivor,” he says, taking a leaf sample for DNA testing.

“Is it just that it’s got lucky? Has it led a stress-free life? Or is there something special about the genes of this tree?”

The conservation scientist from the charity, The Woodland Trust, thinks the secrets of such remarkable resilience lie in its DNA.

The experts want to understand how oaks can live for 1,000 years or more, resisting threats such as climate change and bouncing back from disease – knowledge that could be vital in restoring Britain’s depleted woodlands.

“By exploring the genome of ancient trees, we can understand how to manage them better so that we can secure their future for generations to come,” says Dr Emma Gilmartin of the tree charity, the Arboricultural Association, which is involved in the project.

English oaks are one of the UK’s best-loved trees, growing widely in parks, gardens and the countryside.

They are classed as ancient when they reach around 400 years of age.

By studying the DNA of ancient oaks, the scientists hope to unravel the genes behind the trees’ long life and their ability to survive climatic extremes.

This information would be used to select the best oak trees to plant in the future, to restore woodlands and bring back wildlife.

About 50 of the UK’s most well-known ancient oaks will be studied, including:

The Druids Oak

• Located within a nature reserve in Buckinghamshire managed by the City of London Corporation

• The tree likely dates to the 13th Century, making it older than many historical buildings

• The tree has a girth and height of about 9m

• It has been pollarded, meaning its upper branches were historically cut back to encourage regrowth above the reach of grazing animals, giving it a distinctive squat shape

• Oaks were revered by ancient druids, which may have inspired the tree’s name.

The Crouch Oak

• Found off a busy high street in Addlestone, Surrey

• One of the oldest in the borough, it is believed to be at least 800 years old

• The name “Crouch Oak” may come from the Middle English word crouche, meaning cross, possibly indicating its use as a boundary marker

• It is also referred to as Queen Elizabeth’s Picnic Tree, after Elizabeth I is said to have dined beneath it.

As well as their cultural and historical value, oaks are a haven for wildlife.

They support more life than any other native tree species in the UK, hosting more than 2,300 species, including birds, mammals, insects, fungi, and lichens.

Their leaves feed caterpillars, their bark shelters bats and beetles, and their acorns sustain mammals and birds through the winter.

Some of these species are very rare, such as the Moccas Beetle, which lives on just 14 old oak trees in Moccas Park, Herefordshire.

At the National Nature Reserve adjoining Moccas Park, conservationists are putting oaks at the heart of an effort to restore the landscape.

They are restoring a natural wildlife-rich habitat made up of open grasslands populated with ancient trees, known as wood pasture.

Acorns of ancient oaks that have stood for centuries in the area are being collected and grown into young oak trees, then put back where they once stood. Conifers that weren’t part of the natural habitat were once planted here, but these are being removed and woodlands restored.

This has led to a resurgence of rare species, including hundreds of different flies and beetles, rare bats and woodland birds.

“We’re really seeing a sort of boom in the bird population here,” says Tom Simpson of Natural England, the UK government agency responsible for protecting and improving England’s natural environment.

“In a short period of time – that’s 16 years of restoration – we are really seeing nature recovery on this site. “

As climate change and habitat loss become bigger problems, conservationists want better protection and care for ancient trees. Old trees can’t be replaced – they take decades or even centuries to grow and support many other living things.

Saul Herbert of The Woodland Trust says more needs to be done to protect these “living legends”.

“We need to find out where they are and we need to engage with people and communities to ensure that these trees are valued and looked after for the ecological, cultural and the historic value that they bring to our landscapes,” he says.

Investigators say that the attacker who opened fire on pupils as they were praying at a church in Minneapolis was “obsessed with the idea of killing children”.

Robin Westman, who killed two children and injured 18 others, did not seem to have any specific motive, according to Minneapolis Police Chief Brian O’Hara.

The attacker “appeared to hate all of us”, the chief said on Thursday, adding: “More than anything, the shooter wanted to kill children”.

The murdered children have been identified by family as Fletcher Merkel, eight, and Harper Moyski, 10.

“Yesterday, a coward decided to take our eight-year-old son Fletcher away from us,” his father, Jesse Merkel, told reporters.

“We will never be allowed to hold him, talk to him, play with him and watch him grow into the wonderful young man he was on the path to becoming,” he said.

“Fletcher loved his family, friends, fishing, cooking and any sport that he was allowed to play.”

“Please remember Fletcher for the person he was and not the act that ended his life,” he continued, choking back tears.

“Give your kids an extra hug and kiss today. We love you, Fletcher. You’ll always be with us.”

The parents of Harper Moyski, Michael Moyski and Jackie Flavin, said in a statement that their daughter “was a bright, joyful, and deeply loved 10-year-old whose laughter, kindness, and spirit touched everyone who knew her”.

The family said that Harper’s little sister “adored her big sister and is grieving an unimaginable loss”.

“As a family, we are shattered, and words cannot capture the depth of our pain.”

They added that the family hopes “her memory fuels action” to stop gun violence.

“No family should ever have to endure this kind of pain…. Change is possible, and it is necessary – so that Harper’s story does not become yet another in a long line of tragedies.”

Officials have released few details so far about the suspect’s background, but say she previously attended the church’s school and had a mother who had worked there.

The 23-year-old suspect is believed to have approached the side of the Annunciation Church, which also houses a school, and fired dozens of shots through the windows using three firearms. Police also found a smoke bomb at the scene.

Witnesses have described seeing children bleeding as they fled from the church, begging for help from strangers.

In a news conference on Thursday, acting US Attorney General for Minnesota Joseph Thompson said “the shooter expressed hate towards many groups, including the Jewish community and towards President Trump”.

The attacker, who died at the scene of a self-inflicted gunshot wound, left a note, officials said, but they added that a definitive motive may never be known.

“I won’t dignify the attacker’s words by repeating them, they are horrific and vile,” said Mr Thompson.

Westman’s name was legally changed from Robert to Robin in 2020, with the judge writing: “Minor child identifies as a female”. However, some federal officials and police have referred to Westman as a man when discussing the attack.

Chief O’Hara told reporters that news outlets should stop using the killer’s name, because “the purpose of the shooter’s actions was to obtain notoriety.”

He added that she, “like so many other mass shooters that we have seen in this country too often and around the world, had some deranged fascination with previous mass shootings”.

US officials have warned for years that mass shooting can lead to copycat killings, as killers seek to become famous through their heinous crimes.

Several major news organisations have a policy of not identifying mass killers.

FBI Director Kash Patel has described the attack as “an act of domestic terrorism motivated by a hate-filled ideology”.

In a post on X, Patel said that the attacker “left multiple anti-Catholic, anti-religious references” written on guns and in notes uncovered by investigators.

“Subject expressed hatred and violence toward Jewish people, writing Israel must fall,’ ‘Free Palestine,’ and using explicit language related to the Holocaust,” he wrote.

The killer also “wrote an explicit call for violence against President Trump on a firearm magazine”.

In their news conference, officials confirmed that the attacker had previously attended the school. Her mother, Mary Grace Westman, previously worked at the school, and has so far not responded to law enforcement’s attempts to contact her.

They also confirmed that three residences associated with the attacker, who was from suburban Minneapolis, have been searched by police.

They said that the church locked its doors before beginning its Mass service, likely saving many lives.

Officials added that the guns used in the attack were all legally purchased, that the killer did not appear on any government watchlist, and that police are not aware of any mental health diagnoses or treatments that she was receiving.

Witnesses and relatives of victims who spoke to the BBC have described harrowing scenes of violence.

Patrick Scallen, who lives near the church, said that he saw three children fleeing the building – one of them a girl with a head wound.

“She kept saying, ‘please hold my hand, don’t leave me’, and I said I wasn’t going anywhere.”

Vincent Francoual, whose 11-year-old daughter Chloe was in the church when the shooting took place, said he tried not to panic after he heard the news.

He called it “sick” that children in the US are trained to prepare for mass shootings.

“We live in a country where we train kids what to do. And she did what she had to do,” he said.

“Here it’s a pattern. It’s no longer a freak accident,” he said of school shootings in the US.

“I told my wife that every morning, when we drop our kids, we don’t know if she’d be back safe.”

Mr Francoual, who is originally from France, said that Chloe is afraid to return to school or church.

In the wake of the attack, several lawmakers, including the Minneapolis mayor, have called for the state to enact a ban on assault weapons.

“There is no reason that someone should be able to reel off 30 shots before they even have to reload,” said Mayor Jacob Frey, also calling for a ban on high-capacity ammo magazines.

“We’re not talking about your father’s hunting rifle here. We’re talking about guns that are built to pierce armour and kill people.”