Harry Pitman was attacked at about 11.40pm on Primrose Hill, north London, on Sunday night, the Met Police said.

Police were called to the scene minutes after the attack and officers gave first aid to the victim before ambulance crews arrived. He was pronounced dead shortly before midnight.

Police said Harry was with a group of friends celebrating the New Year when he is believed to have become involved in an altercation "with devastating consequences".

A 16-year-old boy was arrested at the scene on suspicion of murder and remains in custody at a north London police station, the Metropolitan Police said.

Officers have launched a murder investigation and have appealed for information from any witnesses, including mobile phone or dashcam and CCTV footage.

Detective Chief Inspector Geoff Grogan, who is leading the investigation, said: "My thoughts and sympathies are with Harry's family and friends at this difficult time. He was a young man with the rest of his life ahead of him.

"His family are understandably devastated and specially trained officers are supporting them as they come to terms with their loss.

"A dedicated team of detectives are working hard to establish the events that led to such a senseless act of violence. We are reviewing CCTV footage from the area and are carrying out a forensic examination of the scene."

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"We know Harry was with a group of friends near the viewing platform on Primrose Hill where they had gathered to celebrate the New Year," DCI Grogan added.

"It is here where we believe Harry became involved in an altercation with devastating consequences.

"Primrose Hill was very busy at the time and I believe there are people who witnessed the incident who have not yet spoken to police.

"It is vital that we build a clear picture of the moments leading up to, and immediately after, Harry's murder and I need anyone with information about the altercation, or the attack, to contact us immediately."

Police have said that a post-mortem examination will take place in the coming days.

'It doesn't seem real'

Harry's older sister, Talya, 19, has commented on her family's heartbreak following the loss of her brother.

Speaking to the MailOnline, she said her brother could be "mischievous and cheeky" but that he "didn't have a bad bone in his body" and "always stood up for what was right".

"It doesn't seem real," she said.

"I keep on expecting him to come through the front door. His dinner is still in the oven, mum can't bring herself to remove it.

"I'm devastated, he was my baby brother. He didn't even get to see the fireworks, which is why he went to Primrose Hill in the first place."

One woman local to Primrose Hill told PA news agency there were most likely "hundreds if not thousands" of people there at the time of the attack.

She said it was "absolutely tragic and shocking" that a teenager could be killed on her doorstep, adding: "It's not just a young people's party - there would have been families with young children there, too.

"It would have been rammed. It's not just locals - people come from miles around."

Anyone who has information that may help the investigation is urged to contact Met Police on 0208 785 8099 or report information on their website.