Two teenagers were in police custody today after a 14-year-old boy died in a pool of blood near a playground.
The boys, aged 14 and 15, were arrested following the stabbing of Leroy James, Scotland Yard said.
The victim was left slumped against a park wall after the incident in Enfield, north London, on Wednesday as young children played nearby.
Attending the scene of the murder, Leroy's father, also called Leroy, said his son "will forever be remembered" and added that he was "just trying to keep sane".
When asked how the youngster would be remembered among his friends and family, his father said: "I can't explain for his friends, but he will forever be remembered by me."
Arsenal fan Leroy was the youngest of 10 teenagers murdered in the capital this year.
Horrified witnesses described him as "sweet", as his father said paramedics failed to revive him at the scene in Ponders End recreation ground.
Mr James said he was due to take the boy to Jamaica to see his mother in December, and Leroy was looking forward to it.
"He was a pretty quiet boy," he said. "He didn't really talk much."
Mr James, from Edmonton Green, said he last spoke to his son in the morning and that he found out about the attack when one of his son's friends called him.
The 41-year-old scrap metal dealer said: "I was at home. He (his friend) just said to me if I heard what happened.
"I said 'What?' He said 'Leroy has been stabbed and he's been taken to the Royal Free Hospital'.
"But actually he was still in the park until 2am."
Asked what his son wanted to do in the future, Mr James said: "He said he wanted to play football, but he changed his mind all the time."
With two further teenage stabbings in Oxford Street - Britain's busiest shopping area - on Wednesday night, Scotland Yard moved to dismiss fears that London was in the grip of a wave of gang violence.
Detective Chief Inspector Caroline Goode, the investigating officer, said: "There's certainly no evidence or any intelligence at this time that this is a gang-related murder."
Roxy Bagun, 19, who lives on the other side of the park, said she saw Leroy's father at the park on the night of the stabbing.
She said: "His dad was in bits, crying and crying and crying. I just didn't know what to say to him."
Miss Bagun said Leroy was a "good lad" who used to play football and basketball with his friends in the park.
"He always used to come and play football," she said. "My friend saw it all. He told me how he saw Leroy lying there in a pool of blood."
She added: "He was a good lad. I never saw him get into any trouble. They were sweet boys. He just hung around with kids his own age. His friends are so sweet and innocent."
Ben Grant, 14, arrived at the park with a bouquet of flowers for Leroy, who was in the same class as him at school.
He said: "He was really funny and sporty. He loved his practical jokes. He was always there when I needed him."
Leroy was the eighth teenager stabbed to death in the capital this year.
He was pronounced dead at the scene after officers arrived at the scene at 5.30pm.
Ms Goode said in an appeal held at the scene: "We know that the park was incredibly busy at the time of the incident and many more people may be able to help us with our investigation.
"Leroy James was a young person with hopes, ambitions and dreams. Someone has chosen to take those hopes and aspirations away and in doing so has robbed Leroy's family and friends of a much-loved young man.
"We urge anyone who can help, to think about Leroy and their local community. We need to work together to solve this dreadful crime."
Friends and schoolmates reacted with shock to the death as hundreds joined a Facebook page set up in his memory.
"Leroy you was like my little brother and i loved you with all my heart," wrote one friend.
Friends said they were planning a tribute to Leroy, who had a younger brother and sister, at Ryan's Park later.
Enfield Council's Cabinet member for community well-being, Christine Hamilton, said: "The death of any young person on our streets is a tragedy and our thoughts and sympathies are with the family at this terrible time."
A post-mortem examination carried out at Haringey Mortuary found that Leroy died from a single stab wound, Scotland Yard said.