Emergency services were called to Central Park, in Chelmsford, at about 7pm on Friday, where the 21-year-old victim was found with critical injuries.

An Essex Police spokesman said the man died at the scene.

Three suspects, aged 14, 17 and 18, were arrested shortly after and remain in custody for questioning, police said.

The force spokesman said in a statement: "Officers arrived within minutes and found a 21-year-old man with critical injuries. Despite the best efforts of emergency services, he was sadly pronounced dead at the scene.

"His family have been informed and continue to receive support from specially trained officers."

Senior investigating officer Detective Inspector Lydia George said: "This is a deeply distressing incident. A family is grieving, and our thoughts remain firmly with them at this incredibly difficult time.

"I would call on the public and media to please respect their privacy as we continue the early stages of this investigation.

"We are determined to get them answers and build as clear a picture as possible of the circumstances surrounding what has happened.

"We have already made significant progress in our investigation, including making three arrests. We can confirm that we are not currently seeking anyone else in connection with this incident, and there is no ongoing risk to the public."

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Police are continuing to appeal for information, with DI George saying: "Even the smallest detail could prove crucial."

Officers will remain in the Chelmsford area over the coming days to provide reassurance and support to the community.

The Crown Prosecution Service (CPS) said it was working with Derbyshire Police to investigate the use of AI by an officer.

The officer is accused of using the technology to create evidence in a "number of cases", according to Derbyshire Police.

The CPS said it is "engaging with" defence teams and courts which may have been affected by the alleged conduct.

The officer has been taken off frontline duties pending the outcome of the investigation, and no arrests have been made.

This comes after PoliceAI, a national centre for AI in policing, was launched this week.

At the launch on Wednesday, PoliceAI interim director Alex Murray said: "Crime and technology are evolving rapidly.

"Policing must keep pace by adopting AI responsibly to catch criminals and keep people safe."

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Earlier this year, the West Midlands police chief was forced to apologise after it was revealed his officers relied on false information supplied by AI when deciding to ban fans of an Israeli football club from attending a match against Aston Villa in Birmingham.

Maccabi Tel Aviv fans were barred from travelling to the game by the local Safety Advisory Group (SAG), which cited safety concerns based on advice from the police force.

This included a reference by the force to a fictional match, fabricated by AI, between the Israeli club and West Ham United.

The Trump administration cited "national security authorities" and told the company to "suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees", according to Anthropic.

As a result, all customer access to the models has been "abruptly" disabled to ensure compliance, it said. Access to Anthropic's other models is still available.

Although the government did not give Anthropic "specific details" about its concerns, the company said it believes the order comes from a "misunderstanding" over a "narrow" jailbreak.

Jailbreaking is when users manage to bypass software restrictions protecting a cyber network.

Before it was released, Anthropic itself described Mythos, Fable 5's base model, as "too powerful", saying it had an exceptional ability to find security vulnerabilities in software.

As a result, 50 companies were given access to the AI in order to test their systems for vulnerabilities before the public was allowed access.

Three days ago, Anthropic released Fable 5, which is a heavily-guardrailed version of Mythos, to the public.

Immediately, it showed itself to be the most capable AI model available to the public, according to benchmark tests from Vals AI, an AI performance tracker.

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Now, Anthropic says it believes the safeguards it has in place on Fable "reduce the likelihood that Fable is misused for tasks related to cybersecurity".

It added: "In fact, our safeguards are so strong that many users have complained that they are overly broad."

It said it has reviewed a report that it believes the government has based its directive on and found the jailbreak could be deployed by many other models, including OpenAI's GPT-5.5.

"We believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts," said the company in a statement.

"This action does not adhere to those principles."

The UK's AI minister, Kanishka Narayan, said in a post on X the main lesson to take from the withdrawal is that "access to AI capabilities is crucial" as we "debate the future of national security and technology sovereignty".

A UK government spokesperson said: "We are aware of reports that access to Anthropic's Fable 5 and Mythos 5 models has been paused worldwide, including in the US, following an export control directive from the US government.

"We are in contact with both the US government and Anthropic to understand the full picture and are monitoring the situation closely."

Police were called to reports of an incident involving a "small articulated loading vehicle" in the Chalkwell Park area of Southend, Essex, at around 12.30am on Saturday.

Officers said the girl had suffered "significant injuries" and was in critical condition in hospital.

The force added that a man, 18, from Westcliff, and a boy, 17, from Leigh-on-Sea, were arrested. They remain in custody on suspicion of causing serious injury by dangerous driving

A spokesman said: "A group was reported to have taken unauthorised control of a small articulated loading vehicle.

"The girl is believed to have been involved in an incident with the vehicle and sustained significant injuries.

"Officers and ambulance crews attended promptly, and a cordon remains in place."

Essex Police said the girl's family has been informed and are being supported by officers.

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Appealing for witnesses and any videos of the incident, the spokesman added: "We know there were a large number of young people in the area at the time, and we believe some may have witnessed what happened.

"We urgently need to hear from anyone with information or footage."

A team of oceanographers at the University of Hawai'i at Manoa reported two live observations of one of the most elusive sharks on the planet in the Journal of Fish Biology.

Previously, the sharks had only been filmed and reported alive after being hooked on a fishing line and hauled to the surface. There, divers could observe them, but the sharks soon died.

However, while talking to colleagues, the study's lead author, Aaron Judah, heard there had been a potential goblin shark sighting during an expedition in 2019.

That expedition was exploring deep-sea ecosystems near Jarvis Island, a protected wildlife refuge around 1,305 nautical miles south of Honolulu.

"I was shocked to hear this because this species was not known to be in the Central Pacific," Mr Judah said.

He combed back through footage from the expedition and discovered that the team had, in fact, documented a goblin shark during a livestreamed dive northwest of Jarvis Island.

A second sighting came about when a team exploring the Tonga Trench in 2024 captured footage of a goblin shark in its natural habitat using a baited camera.

"The Goblin Shark is one of these deep-sea charismatic animals that I never thought we'd see alive, and then to do so was amazing, but to then learn that colleagues in Hawai'i also saw one was just incredible," said Alan Jamieson, professor and founding director at the Minderoo-UWA Deep-Sea Research Center, who documented the 2024 sighting.

Mr Judah said seeing the "most iconic of all the deep-sea sharks alive and looking healthy in its natural habitat" was a "unique honour".

"I was also very surprised about how deep this species was found. The observation from the slope of the Tonga Trench is nearly 700 meters deeper than this species was known to live," he added.

The new observations significantly extend the known range of the sharks, both in terms of depth and geography.

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"New discoveries like this demonstrate that there is still so much to explore in our deep-ocean home," Mr Judah said.

"Given the newly expanded geographic range of the goblin shark, this species can be included in regional management and a nation's biodiversity list, whereas beforehand we didn't know it was even there."